I know I'll get universally lambasted for this, but I preferred RE5 to RE4... mainly because RE4, to me, always seemed like there was always an abundance of ammo. It was literally like shooting fish in a barrel. RE5, at least made me feel like I had to conserve to a degree.
Also, please don't forget how good RECV is... IMO one of the best(if not THE best) in the series.
RE3, is actually one of my favorites... many people didn't like it because it was significantly shorter than RE2. Remember though, the premise of RE3 is about TIME... and lack of it. RE3 is the only game where you truly feel a sense of urgency, like you're racing the clock. See, RE3, when played properly, you're supposed to fight Nemesis EVERY TIME, finish the game quickly, complete all the puzzles, and also NOT USE FIRST AID SPRAYS. The trick was conserving ammo, dodging unnecessary zombies, not needing to heal, and you had to do all this QUICKLY. For that, RE3 will always be one of my favorites... its a very underrated game.
RE4 was good, it just wasn't memorable to me because it wasn't RE. I still liked it though.. it was fun to play.