Oh god my 64. Happy to say I still have it in working condition, and so does my cousin with his, so we can go back to some of those old games and enjoy the nostalgia.
1. The Legend of Zelda: The Ocarina of Time - this game occupied so much of my spare time when I was younger. So much time lost, but not wasted. Good memories reside here.
2. GoldenEye - The multiplayer. When I was in primary school, I was king of GoldenEye multiplayer. No one could best me. And this is without the Golden Gun too. Plus the Firgate mission rocked.
3. Conker's Bad Fur Day - Unfortunately my parents wouldn't let me buy it, but my cousin STILL has it, so we go back to the multiplayer of it occasionally. Great fun.
4. Super Smash Brothers - If I chose Kirby, everyone was basically screwed. Unless my friend chose blue Kirby. Then it was even. Many fun, even, challenging fights.
5. Lylat Wars - Like someone else mentioned (whose name I can't remember) the game that me first start worrying about scores. Man, that was FUN.
I had fun. And just with the single player. The multiplayer was even better. I loved the N64. It defined a big part of my childhood.