Football is the only sport I'm really into, but I watch a little basketball too...
I am a HUGE Saints fan - through thick and thin... I love them. It's actually a little past obsessive and into the realm of sick.
I really enjoy the people involved in the games, so I follow players pretty closely. While the Saints have no competition for first in my heart, my second place team will change based on the players and coaches. If I like someone, I want them to do well.
On the other side of that coin, if I don't like a player or coach, I generally want the team to fail. I also develop theories about off field behavior based on my feelings about a player.
On that note, I maintain that Tom Brady kicks puppies for fun. That "nice guy" persona is totally fake. It has to be - you can see the evil in his eyes. I take it personally that Ben Roethlisberger can't seem to be nice to Bill Cowher, who seems to be a really great guy.
I love Notre Dame, adore Charlie Weiss, and cried every Saturday of the 2007 season. I'll talk about them more when I have something nice to say.
I follow Florida and LSU also - but not with the same passion.