Seattle - because of their lively play, Drew Carey, atmosphere, colors and X-Box insignia.
Portland - because of their stadium and environment; the soccer equivalent of Wrigley or Fenway.
Kansas City - because of Zusi, Feilhaber, Kamara, their stadium (one of the best), their style of play, and this: Image: http://26.media.tumblr.com/tumblr_m1271saQcG1r1fq7do1_500.gif
LA Galaxy - the MLS equivalent of Man United, I still like them for their colors, kit, Beckham, Donovan, and Magee.
Chivas USA - they can frick off and die.