One fun multiplayer deck a friend I saw used Pestilence, Urza's Armor, Mana Flare, Repercussion, Ogre Enforcer (I preferred Cemetery Gate, but this deck used the Enforcer), and Bubbling Muck. The whole Repercussion/Pestilence engine thing was just so deadly to most opponents, and with Mana Flare, Dark Ritual, and Bubbling Muck all available as mana acceleration (this was before Cabal Coffers was printed, so don't even ask about that, and the guy might have had Lake of the Dead in the deck for a while, but not when I played it, so I don't know how that worked out) the deck was capable of ridiculous damage that would end the game on one turn (and sometimes rather early in the game).
Of course, anyone familiar with the deck would not assume that the Mana Flare was out there to help everyone have a good time. It's decks like this one that make people realize that countermagic can be a good thing to have in multiplayer games (just say NO to Pestilence).
Mana Flare/Palinchron could probably be quite fun (infinite mana). I have both cards, but I never tried it (probably because High Tide always looked easier).
