Just a few off the top of my head:
- Contra
- Any N64 wrestling game
- Mario Kart 64
- Smash Bros. and Smash Bros Melee
- Beat em ups like Final Fight, Double Dragon, Streets of Rage
- Street Fighter II/Mortal Kombat
- NBA Jam
- I'm gonna stop myself here
Just a few off the top of my head:
RE: Old School Games I Wished Had Online Multiplayer