Mario Party 2
I was recently reminded how great the multiplayer is, so although Mario 64 might be the best and most important game, I think I enjoy Mario Party 2 more. GoldenEye, Mario Kart 64 and Tony Hawk's Pro Skater are also very close.
azuarc
wasn't even home. he was playing Magic the Gathering at his buddy's store, which is extremely easy to verify