Most horror fans know why they can walk into any store where movies are sold and find multiple versions of Night of the Living Dead on the shelf - a copyright snafu back when the film was released sent the film into public domain almost instantly, leaving its creators out of its very lucrative earnings over the years. In fact, part of the reason George Romero got involved with the 1990 remake (which he wrote and produced for director Tom Savini) was to finally get a piece of the film that defined his legacy - a noble excuse for what was actually a pretty good update (I actually prefer the 1990 version's ending, with Barbara shooting a non-zombie Cooper out of spite). Romero and his partners were more careful with the first sequel, 1978's Dawn of the Dead - apart from the official remake in 2004, the title has not been used anywhere else, and so horror fans have never been duped into buying some garbage knockoff film with the "Dawn of the Dead" title slapped onto it. Unfortunately, 1985's Day of the Dead was not so lucky; you won't find the classic original in any budget packs or anything like that, but it seems the title itself is fairly easy to obtain, as there have been three remakes/sequels over the past thirteen years, none of which involve Romero in any way or bear much of a resemblance to his film.
Interestingly, even his own film is pretty different than the one he originally wrote. After the success of Dawn, a producer named Salah M. Hassanein offered Romero a three picture deal under the condition that one of those three films be another Dead film. Romero was a pretty smart guy, and knew that there was no rush to make the sequel first, because Hassanein would always want to make that (whereas if he made it first, Hassanein could reneg on the deal, having gotten what he really wanted), so he put the Dawn followup on the back-burner, focusing on his other ideas first, while also giving him time away from zombies for a bit so that he'd be more excited about doing it when the time came. Thus, the first he made under the deal was his most personal film: Knightriders, which was unfortunately a flop. Luckily the next one they made together was Creepshow, a genuine hit (Romero's only film to hit #1 at the weekend box office, in fact), but since the film was bought by Warner Bros for distribution they didn't reap many of the rewards of its success. So now the time had come to finally make the next Dead film, but there wasn't much money left for it due to the lack of much income from the first two films they made under the deal. As the story goes, Hassanein once again offered Romero a deal: he could get seven million dollars to make an R-rated Dead film, or about half that to go out unrated. I'm not sure how long Romero considered one form of restriction versus the other, but ultimately, as we know, he went with the freedom to be as gory as he wanted.
Of course, this meant that the script he wrote had to be reworked to accommodate the much smaller budget, so it now had fewer locations, fewer characters, fewer big action scenes... you get the idea. But honestly, I think Romero got a better film out of it, even if it (in my opinion) didn't quite reach the highs of Night or Dawn. Yes, it's a bit slow in spots and some of the acting is questionable, but the climactic sequence of zombies overrunning the place is better than the similar sequences in the first two entries, and its themes of moving past the idea of "saving the world/fixing the problem" onto simply trying to live within its reality for the rest of your one life have really stuck with me over the years. The scene where lead hero Sarah visits the only two military guys who aren't assholes (John and McDermott) is my favorite scene in the film by a mile, with John mocking (in a gentle, friendly way) what Sarah does and trying to get her to look at things from his point of view, and that people playing God might very well be the reason He inflicted the curse on the people, to remind them of who is "the boss man".
Now some might find that scene a bit heavy handed, even if it's in line with the famous "No more room in hell..." speech from Dawn with regards to chalking up the zombie plague to something more biblical than scientific, but trust me, it's practically atheist compared to the rantings you can find in Romero's original draft, which is easy enough to find online. The original incarnation of Logan in particular was prone to offering bible quotes and outbursts like "Fallen angel! This is the Judgement Day, when you will burn for your sins! The Lord will cast you down to the lower reaches!", while another character recited the standard Act of Contrition at one point. Unlike in the finished film, where God was invoked to actually say something, these characters just came off as religious nutjob stock characters that you've seen in other horror movies, and it would have been fairly annoying to listen to had Romero shot this script as is. But while even Romero agrees that the reworked version that he ended up making was superior, his original script would have overall been a solid movie in its own right, and it's worth taking a few seconds to find it online and compare for yourself.
Luckily, Romero was able to use some of its budget-restricted ideas - such as upper class jerks walling themselves off and leaving the less fortunate outside with the zombies - for his own Land of the Dead in 2005. Coincidentally, that same year was the one that the world was blighted with the first Day spinoff, titled Day of the Dead 2: Contagium - which despite the "2" is actually presented as a prequel to the original film. It starts in 1968 (same year as Night, yes) with the first signs of a zombie outbreak, then flash forwards 37 years later (yes, now PAST the timeframe of the movie it's allegedly prequelizing) to tell an unrelated, wholly stupid story about a bunch of very unlikable people in a hospital, with an outbreak spreading thanks to a thermos that was sealed in the 1968 sequence. It's a damn near unwatchable waste of time from the same people who inflicted Creepshow 3 upon us, and akin to one of those "sequels" to Lucio Fulci's Zombie where they just slapped the title on an unrelated film just because it had zombies in it, even if the "rules" were not the same. Same deal here: the look of the zombies is different, they talk, the infection is described as a mutation of human DNA (which has no relation to anything that was established in Day or any other Romero movie), etc. It is in no uncertain terms, a shitpile of a movie anyway, but putting the "Day of the Dead" title on it makes it so much worse.
And if you're wondering how this sort of thing can happen, I'm not entirely sure. European copyright laws are different which is why you see so many unauthorized/unrelated "sequels" in Italy and the like, but over here you have to go through the proper channels to avoid being sued. However he did it, the film's director, James Dudelson, apparently got the rights to the titles of those three films Romero made for Hassanein, because he also made the aforementioned Creepshow 3 and was even threatening a Knightriders sequel at one point. I assume the total failure (and near universal hatred) of the two films he did make are the reason he has been so far unable to get another Knightriders or his announced Day of the Dead 3 (subtitled Epidemic) off the ground, but he's still listed as a producer for the two Day of the Dead remakes that followed, so he must still be holding on to those rights in some capacity*. The first of which, 2008's simply titled Day of the Dead, is the biggest budgeted of the lot, and the only one of the three that followed Romero's that at least sounded good on paper. The director was Steve Miner of H20 and Friday the 13th Part 2 and 3 fame, and the script was by Jeffrey Reddick, who wrote the original version of Final Destination. The cast was also good or at least known: Mena Suvari, AnnaLynne McCord, and Nick Cannon were the leads, along with Ving Rhames as Rhodes, a nice "get" since he was in the Dawn remake (albeit as a different character, though I'm sure some less astute fans didn't notice and took it as a sign that this was a legit followup to Zack Snyder's film).
It's not a good movie by any means, but I don't think it's AS bad as its reputation suggests. It's got a lot of very stupid shit like zombies crawling on the ceiling, and Cannon's ad-libbed attempts at humor are largely terrible, but it's a decent timekiller with an admirably fast pace (its reported $18m budget is on the screen, at least). Miner can actually direct a coherent action sequence, which puts it above most DTV zombie fare of the '00s, and if nothing else, it feels like a real movie, unlike Contagium. But it's a shame that it could have been better; from what I understand, its myriad producers were all determined to put their stamp on it despite having conflicting ideas of what the movie should be, and at least one of them kept whittling away at things that would have kept it more in the spirit of the original. Basically, the movie is a bit messy, but fine, and its poor reputation has more to do with its title/remake status than its actual on-screen quality; had they dropped the few character names (Rhodes, Bub, and Logan) and released it with some generic title, it would probably have a higher IMDb rating, if nothing else.
That said, its 4.5 rating is much better than Contagium's 2.2, and also better than the current 3.4 for Day of the Dead: Bloodline, another remake (despite the sequel-y sounding subtitle) this time directed by The Corpse of Anna Fritz filmmaker Hèctor Hernández Vicens. As with the others, it's not very concerned with locking all of its characters together in a bunker (something I never understood about these followups - wouldn't it be cheaper to have just the one location?), though it restores the "scientists vs military" angle of the original that was absent from the others. But there's no Doc "Frankenstein" Logan this time around, just heroine Zoe Parker (Sophie Skelton) who is working on a cure/vaccine for the zombies and using her military boyfriend to help her get zombie specimens without his brother finding out, as he was the one running the base and didn't want zombies being used for anything except target practice. This guy serves the same purpose as Rhodes in the original, but his name is Miguel, a naming switcheroo of no consequence, and in fact it might just be coincidence that the name "Miguel" appears in both films, since there are no other holdovers, possibly for rights reasons. This is most obvious when it comes to the character played by Johnathon Schaech, who is like Bub in nearly every way - even the makeup and clothing are pretty similar - but his name is Max. Perhaps the 2008 film retained some of the character rights (they're so mangled in this franchise that even Romero had to jump through hoops to use Savini's generic "Biker" character in Land of the Dead) and they couldn't get them here, or they just wanted to carve their own path a bit, but either way I found it a bit odd that they'd go through all the trouble to recreate Bub but not use the same name.
Ultimately, like the 2008 one, its just kind of a generic zombie movie that no one would think much about either way if it wasn't tying itself to a classic. There's nothing particularly terrible about the film, and it even earns a few points for using practical effects in many of the scenes (though it's got CGI blood too), but there's nothing here we haven't seen before in this played out sub-genre. Plus, there's an unfortunate rapey element (Zoe realizes Max still has some of his human qualities because he licks her instead of trying to bite her), and also no real sense of a world on its last legs, which is one of the things that made the original Day so great (in that film, Logan calculates that there are now 400,000 zombies for every one human left alive). In fact, we see the outbreak occur in this one, which seems like a waste of time at this point for any zombie movie as we've seen these scenarios a million times and they're all pretty much the same. It borrows a few of the original's scenes (such as a mishap when trying to wrangle a zombie for testing), and they spend a bit more time in a bunker than the previous remake, but overall it's a shame that what could have been a halfway decent original zombie movie will largely be seen as nothing more than an unnecessary cash-in, likely wasting some of its budget to obtain rights to the title instead of putting that money on the screen.
When Bloodline was announced, the producers said it would "be closer to Romero's version", but that could have meant anything. To be fair, it is indeed the closest any of the three have come to resembling his film, but they're still even further apart than the two Dawns were. It's just amusing to me that Romero himself wrote two versions of the movie, and no one has ever tried using his other script and presenting it as a sequel/remake/whatever (there is a precedent for such things; when Sony made a DTV sequel to their box office hit The Messengers, they simply went back and shot Todd Farmer's original Messengers script, since it was so heavily rewritten for the finished film). Again, I don't think it would be an improvement on the version he actually made, but it would certainly be more interesting to see that vision come to life - not to mention more worthy of the Day of the Dead name, with Romero's own words guiding it for once. With Bloodline just dropping today, I doubt anyone is scrambling to make another one just yet, but if it's legally possible, maybe they can use that script in ten years when it's apparently time for the next remake? Fourth time's the try!
*I looked around online for a bit to see if I could find any info on this deal he must have made, but found nothing substantial. If anyone can shed some light on it, feel free to comment below, as I find it kind of fascinating that he is seemingly legally cleared to use these rather lucrative titles.