Eh, I actually grew to like RE 4, even though it was a radical departure from what the series had been (no Zombies, just infected and unintelligible weirdass 'village' people), but there was still enough puzzles to solve and items to pick up to keep my interest. I liked the fact I could 'buy' the infinite Rocket Launcher the first time around (although it took to near the end of the game to do so) and the weapons upgrades, and that I could go back into the replays with full weaponry.
What I didn't like was that stupid sea monster, Ashley's stupid screaming "LEON" all the goddam time, and not being able to bang the dumb bitch at the end (like, here's a sexy bitch just throwing herself at Leon, and he turns her down, WTF ?). But the later ones in the series were even more of a departure from that still, and that killed it for me.