Honestly, I think none of them are really good. Better than the live-action crap, sure, but that unfortunately didn't set the bar very high.
The story of Degeneration is solid in that it makes sense from the beginning to the end, something that can't be said about all the games (or movies), but it doesn't show or tell us anything new. Leon is basically a robot, I don't care about his implied love story with yet another forgettable one-off character, and there's only so many cool lines and bitchslaps Claire can deliver to make the entire thing more enjoyable. Still my favourite out of the bunch, though.
Damnation could have been more interesting as both a movie and an addition to the game franchise if it told the story of Edonia leading up to the events of RE6 rather than inventing yet another Eastern European country for a completely unrelated tale that only serves to highlight how badass Leon is. (And even that falls flat because the real badasses of the story are once again the women.) I'm also not sure I completely understand the story because my brain goes on standby whenever politics come up.
Vendetta... oh dear. Where do I even start? Once again Chris finds himself on a mission that he emerges from as the sole survivor - seriously, it's getting old -, and they also stole his character arc from RE6 and gave it to Leon this time. Speaking of Leon, those action sequences of him wrecking a highway with his bike stunts only look cool until you realise there's probably normal people sitting in those exploding cars, and it doesn't stop there, the entire movie tries way too hard to impress us with over-the-top demolition and violence and then closes with a wannabe-happy ending about zombies turning back into normal people... WHAT? Rebecca is back, once again as a damsel in distress with little purpose who for some unexplained reason is still wearing the same outfit as back in 1998, never mind that it was actually a uniform back then, and we get a handful of new characters that nobody cares about. Parts of the movie can be enjoyable, but during other parts I just sit there wondering who came up with this $hit and how the hell it ever got approved. Replace either Leon or Chris with Alice and this could easily pass as one of the live-action movies, but I suppose that would go against Capcom's most likely intention behind this mess, to create a story about the franchise's two male leads working side by side after a similar idea for RE6 wasn't properly explored. The trailer looked interesting, but the film itself... meh.