I've been trying to play the REmake recently from borrowing it off a friend and I swear it seems infinitely harder than the original PS1 game.
Ammo is far more scarce than I remember, the zombies take alot more knocking down, it's brick!
Personally 4 is the best of the series but out of the 'old style' RE games, it's gotta be 2. Also, I think I'm one of the few people who really loved 3 as well.
1 was great and it did set the path for RE but I think it was outdone by it's sequels.