I was just wondering what some of you guy's favorite levels are?

Mine is Hazy Maze Cave.

That is a difficult choice, it being my favorite game. I probably remember Tick Tock Clock most fondly, but the first snow area (I can't remember what it is called) is also really great.

That game just has great levels.

Tick Tock Clock,
creative stage with tricky platforming-

Oooh.  Tough one.  I originally wanted to say Big Boo's Haunt because it had that creepy merry-go-round in the basement, but I think on further review I also have to go with Hazy Maze Cave.  Mostly because that level has a lot of variety.  There's the hill with the rolling boulders and the giant bottomless pit.  There's the actual Hazy Maze.  There's the area with the elevator lifts.  There's the secret area where you get the metal cap.  There's the underwater lake with Dorrie the plesiosaur (which, as you approach the lake, the music changes form the chill "Mario Underground theme" [which is awesome in itself] to that creepier, mysterious music).   Even how you get to the level is cool - jumping into the pool of liquid metal...or oil - whatever it is.

@Kjellm87 said:

Tick Tock Clock,creative stage with tricky platforming-

Are you some kind of crazy person?

The best level is the first snow level.

To me Bob-omb Battlefield will always be the most memorable level of Super Mario 64.
 
It had a great boss, that mother fucking Chain Chomp, wing hat, koopa racing, canons, all that shit.

Hazy Maze Cave. There was a lot of cool shit in there, but most of all I loved the background music for it.  

Little Big World.. I loved the mechanics of that level. Although that second foot-race with Koopa was a BITCH

The first world is my fave, the water world on the other hand is not

@LordXavierBritish said:

To me Bob-omb Battlefield will always be the most memorable level of Super Mario 64. It had a great boss, that mother fucking Chain Chomp, wing hat, koopa racing, canons, all that shit.

Yep, all you need is in that level.