Well let's see, since Super Mario 64 has already been deemed an unusable answer...
I think my favorite N64 game would have to be a toss-up between Star Fox 64 and the original Super Smash Bros. I never owned an N64 myself, but I have friends who did, and those were the games that I played the crap out of on their systems.
Diddy Kong Racing 64 was an amazing game, or at least to a five-year-old. You could fly backwards, you could have (actually pretty lame, thinking back on it) pick-ups, which were pretty cool at the time, and I think you could play as Banjo in the game, which is of course awesome.
I really enjoyed Jet Force Gemini that game was great. I used to play it all the time. It was a pretty cool space adventure for its time, plus the multiplayer and mini games were a lot of fun too. And I was really happy when i was the first to find all the tribals and unlocked the asteroid to fight Mizar before all my friends. Also the cluster bomb was cool.
Banjo-Kazooie!!!!
Oh I love that game. Yes that's in the present tense. I now longer have an N64, which fails because i used to have a couple of good games... none of which i can actually remember other than Banjo... but thanks to the magic of emulators, my childhood favorite lives again. I love the music in the opening screen. And i never get tired of going back to the first level to be a termite again.
Hands down Paper Mario. I learned to read playing that game. (It came out when I was about five) I remember falling asleep playing that game because my eyelids were too weary to stay open. Collected all the badges, beat the Dojo master 3 times, and delivered all the mail. Baking the cake was a nightmare though, took me at least 20 tries.
Star Fox 64! It was the culmination of everything that was started (graphics, level design, sound) on the SNES original. In other words, Star Fox 64 looked like what we imagined when we played the SNES original... that my friends, is what a game sequel ought to do! Plus it introduced rumble 'fer cryin' out loud (and where would we be without rumble?)
pokemon stadium was my favorite N64 game. I never actually owned a n64 but my friend had one and I thought it was pretty awesome. I played ever timealso was a pokemon fanatic at the time so that boosted my love of the game.
My other favorite was one of the mario partys (2 or 3). You could as DK in it.
Damn you and your "OOT = Hammer"!
Hmmmmmmmn....It's hard to say.
Probably Super Smash Bros.
And in the early days that I owned my N64, it was Pokeman's Stadiumz.
definitley mario tennis i dont need that "new play control" im fine with the a+b buttons thank u. I remember playing that game as a kid i loved it (even though i would always lose) then i was playing it a couple days ago b/c my n64 and games got stolen a while ago and i realized how to do power shots and I pwnd! My fav. character was birdo but after looking at a certain article and a video I learned birdo was a guy so ive chosen daisy insead i just recently got the gameboy version and trnsferd new characters over i stil like daisy but now i have bragging rights to my friends who dont care
Star Fox 64 is still one of my favorite all-time games. It had fighter ships, it had stuff blowing up, and it had an annoying frog you could slowly watch die and laugh about to your friends.