Well the Houston rap scene is about the best in the nation as far as im concerned. I lived there for a few years and I cant really get into east/west coast stuff. Devon the dude, UGK, SPM, Rasheed, Lo-G, Screw, Scarface there is just to many to name. Anything from www.dopehouserecords.com or www.swishahouse.com records really.
For non south rap, I like dayton family, trick daddy (miami), E-40 (thats just the way it is) and quite a few others but thats the main stuff.