NBA: Rockets MLB: Expos NHL: Ottawa Senators (I cheer for all Canadian teams, though) NFL: None really... only started watching football a few years ago, so probably the Texans.
NBA: Rockets MLB: Astros NFL: Cowboys NHL: Don't really care any more but used to be Dallas Stars I think this is somewhat common. I mostly just like the Texas teams or Houston teams to be specific, except for the Cowboys. I only really had them to cheer for when I got into the NFL, so that added to the fact that my familiy is a big Cowboys fan got me into them.
Hockey is a great game, but not on TV. Of course, not having an NHL team makes it difficult for me to muster any interest in the NHL. And the fighting is stupid - I prefer the skill, grace, and power of the non-goons. If I wanted fighting, I would watch boxing. Otherwise I am a Houston guy. Yet, I have no emotional attachment to the Texans because I hate the NFL and I will never again invest any emotional energy in one of their franchises. I find today's NBA to be a snoozefest, though I do like Yao and the addition of T-Mac might revive my nearly comatose interest in that sport. The Astros - well I either love em or hate em - what a rollercoaster of a team they have been this year.
in order of most favorite to just well...favorite NBA: Rockets/Spurs/Kings MLB: Red Sox/Astros/any team that beats the Cubs NFL: Patriots/Texans/Packers