Azorious
Selesnya
Rakdos
Golgari
There isn't a deck that is screaming "must use" from these four. Each has something good to offer. The Azorious deck seems the weakest because I do not have any useful abilities. The Selesnya deck will allow me to drop some 3/3 tokens (but without trample) and gain some life. Gaining life is great but tends to delay the inevitable if not coupled with something else to do life-taking. I like the Selesnya selection but Rakdos and Golgari feel like stronger decks. The Rackdos selection has the only really good rare I pulled: Slaughter Games. Deviant Glee allows me to enchant for trample and I have two of them. But wait, I have three Selesnya creatures that are three drops with three power and three toughness.... I think its down to Selesnya and Golgari, just like my preferences before the pre-release. I don't like all the sacrificing in my black selection even if I have some good scavenge cards. Yet some of the latter are a little heavy.
And the winner is: Selesnya. I can play three three-drops that are 3/3 (quite the tongue twister).