I need help finding some really awesome multiplayer games.

What I'm looking for is something that you can pick up or put down at really anytime. My friends and I have been playing Mario Kart 64. For 5 months. It's time for a new game. Two games I have in mind right now are Road Rash 64 and Timesplitters 2.

I'm kinda looking for shooter games, but ones that are not related to war or political intrigue or anything stupid like that. Just a game where you run around killing each other. So no Call of Duty or whatever the hell you people play these days.

Not really looking for anything cooperative. Competitive plz.

ALSO, it should to be for N64 or PS2. PS3 recommendations are appreciated though.