I've been on a bit of a Biohazard kick lately. I really like a lot of the games in the series, though I must admit that I've never finished the first game (I really need to address that). I have completed Resident Evil 2 (PSX), Biohazard 4 (PS3), and Biohazard 5 (PS3). I lost interest in the series with Biohazard 5, which has some excellent combat but a really juvenile story that's bizarrely all about the power of friendship.
Biohazard 6
This is the game that killed the series for a while. I remember playing the demo on PS3 and absolutely hating it. It is such a PS3/360-era game... tons of sequences where you just walk slowly down a hall while listening to exposition, QTEs, objective markers even though levels are just corridors one after another. The framerate was also quite poor on the PS3, making the game uncomfortable to play.
The PC port is a massive improvement. It supports high refresh rates, and can be played at 60 fps (or "variable," which is 120 fps but breaks some parts). You can even disable the QTEs. Of course, it can't correct the PS3/360-era design of cinema scenes connected by runs down corridors (Capcom should be remaking this game, not masterpieces like Biohazard 2 or Biohazard 4), but you can now at least appreciate the awesome combat. Whenever you run into a group of zombies, the game goes from 4/10 to 10/10. This game is not a survival horror game; it's basically a 3D version of something like Final Fight. You're scanning the environment, dodging attacks, positioning yourself in the optimal locations, roundhouse kicking groups of zombies. It feels awesome.
Biohazard 7
I had this on PS4, but I always prefer to play a first-person game with a mouse, so I got it on Steam. I first played through the demo, which is a unique scenario taking place in a small portion of the map from the actual game.
As a fan of gritty and gory 70s/80s horror movies, I like it... but it feels more like something like Outlast than a Biohazard game. On the other hand, as a fan of horror movies, I was disappointed to see a sort of cargo-cult design mentality. It feels like something designed by people that don't really like horror movies, but just looked up modern horror cliches and put them all in the game. The game would also be very annoying to replay, thanks to all the cinemas you can't skip, s-l-o-w segments where you just walk and listen to exposition, etc. When will game developers finally realize that no on wants to just slowly walk down a hall/valley/cave listening to story?