All of them were awesome and some of my favorite movies ever...except that abomination which shall not be named! Resident Evil: Retribution! Pft! Terrible!
If we're talking about the games, 3 is my favorite, and I'm hoping we get a game that's a return to that form but with some modern updates. But, I could also live with a game more in line with RE4.
Resident Evil Zero, REmake, 2, and 4 were awesome. I feel like it has lost its creepy factor after 4. I really liked certain bosses like William Birkin and Lisa Trevor, not only were they not too hard to defeat (but hard enough); I liked how they had a comprehensive story background to them, especially Lisa Trevor. Seriously, Lisa Trevor is one boss who you can feel really bad for and kinda regret killing.
I used to enjoy it, yeah. Resident Evil 4 was my favourite, but I enjoyed Resident Evil 5 as well (Chris is a hottie, albeit a fiction hottie, lol). I hated those chainsaw guys though.
I've played 5 and 6, liked them but didn't see anything that made me crazy about the series like some people are. The villians in the series such as Wesker are pretty cool though