...mainly because that's all I've played anywhere close to extensively. The only decks I've actually built for the current Type 2 are Sligh, U/W/b beatdown, R/G/w token swarm (pretty fun), and Rebels. Rebels are fairly fun to play, and I'm constantly surprised/amused by the power it has to swing a game through sheer relentlessness.
U/W control was a ton of fun the one day I played it, but that might be because it was a big change for me. Ya gotta admit, bluffing counters can make for a good time.