Best Multi-player?

Offline, in a four player split screen multiplayer, it's tough. Many fun times back in the day with Goldeneye, and many fun times still with Halo. And then of course there is Timesplitters 2, which is a helluva lot of fun to play too. I really couldn't decide.

And then if you consider online multiplayer games, I'd have to go with Raven Shield, or maybe Counter-Strike. Both brought me countless nights of fun.

EDIT:

Oh, and besides shooters, I can't ignore Super Smash Bros. Melee. That kept me and my friend's eyes strained for months. Even though I never could get too great at it, continously counter-attacking everyone with Marth was one of the most entertaining things of my gaming history.