I currently have seven decks, all are type anything goes and all but one or two are designed for multiplayer.
White Angelic Life Gain: with Serra Avatar, Angelic Chorus, Noble Purposes, Congregates, and a ton of other enchantments to fuel my Serra Sanctum.
R/B drop deck: Hymns, Duresses, Ostracizes, Megrims, Coercions, Unnerves, Greel, Latulla, Avatars of Fury, Ball Lightning and other assorted creatures; want the new Blazing Specter for this deck.
Green Beat Down: Tons of elves with priestesses and Rofellos to fuel my Avatars of Might, Force of Nature, Dual Natures, Deranged Hermits, Verdant Forces, Verdeloth, and Coat of Arms; it's real fun to have three Dual Natures out and get a Hermit.
Red Cheese: tons of small hasted creatures, Suqata Lancers, Raging Goblins, Fervor, with a Rathi Dragon as the finisher if my Infernos would take me out too.
Vampiric Conspiracy: Lot of huge black or gold legends with Conspiracies and Belbe's Portals to turn them all into Vampires and get them for three, great with Spirit of the Night and Baron Sengirs.
Counterspell/Blue Beatdown: mono-blue with Tidal Krakens, Clones, a Doppleganger and other big menies backed up with 12+ counterspells including Quash and Force of Will, also has Rhystic Study, Library of Leng, Ivory Tower for life gain and Treacheries/Dominates to steal their good stuff.
Speed Green: with Llanowar/Skyshroud Sentinels, Howling Wolves and various pump ups with land search cards.
Artifact: no basic land whatsoever with all the Urza's Lands, a Sentinel or two, and teeka's Dragon as the main killer especially when combined with Dragon Blood and Extruder.
B/W Shadow: name says it all, lots of small Dauthi and Soltari creatures with flanking knights as support.
Ok that was actually nine, but oh well that's all of them. Although I am trying to rebuild my Sliver deck with Invasion cards as a source of new gold cards, going to be 5cG.