Resident Evil. It's slightly odd to say that too, in that I hate the original games because of their control schemes. Those are garbage control schemes that were only mildly improved in the recent re-releases, but still weren't very playable to me. I love the cheesy, awful, monsters and stories, they are hilariously terrible B-Movies, but they have their charm, which is a bummer that I couldn't get into them.
I think I did manage to beat RE3, but I didn't really like it too much. Resident Evil 4 though, like probably a top 20 game of all time for me. I put tons of time into the Gamecube and PS2 versions. Didn't like the Wii version because I'm not fond of motion controls. I also like Resident Evil 5 despite its faults...RE6? Oof...Yeah lets move on from that. Revelations 2 was generally alright, though I couldn't get too into Revelations 1 very far, though that's mostly I think just because it was a handheld port. It was an alright port, but you can kinda tell it wasn't made for the big systems.
I also put RE higher, just because I haven't played the SH games much. I dabbled in 3 and 4, very creepy, very unsettling games. It's what the RE games were missing, because they were never scary, though hopefully that's being fixed with RE7 if the standalone demo is any representation.