Because I feel like it
the Incredible Hulk: I put my money on the Colts, so that's who I'm rootin' for, 'cause all I care about is gettin' mine. I swear, if that brat Rick Jones interupts this game I'll snap him in half. Oh, crap, it's four o'clock, time for my personality to change! Stupid Stan and Jack!
Savage Hulk: Hulk like Bears! Puny Banner probably likes the Colts because they are a finesse team! Hulk Smash Banner like Bears Smash Colts! Oh no, Hulk to excited from smack talk, or perhaps Hulk came in to contact with sunlight, Hulk not sure, turning back to Banner...
Dr. Bruce Banner: Oh God, what have I done? My clothes are torn, my apartment is a mess, and I'm wearing a giant foam finger and a beer helmet; did Hulk invite a bunch of guys over to watch the Super Bowl? Because I don't care for football! It makes me angry. And... hell, you already know the rest. I wanted to watch the Discovery Channel all day!
Iron Man: I pick whichever team has an absurdly elaborate plan for victory. Like me. I do that kind of thing. You might even call me the kind of guy who could start a civil war; if you were really unsubtle. Jeph Loeb does that every time I see him. So, anyway, since Tony Dungy seems like the kind of guy who would take samples of Peyton Manning's DNAÂ and unleash a psychotic clone of him if the chips were down, I'll go with the Colts.
Thor: Verily, it shall be a tremendous contest of athletic achievement on yon field of battle, not unlike the sort of contests the Odin Son engaged in with the Frost Giants in days of yore. Lovie Smith doth remind me somewhat of most exalted Odin himself, and Brian Urlacher is a spitting image of the God of Thunder in his younger days, so I shalt choose the Bears! Because the Colts are pussies, just like those Frost Giants.
Captain America: Football sure has changed since the '40s. What happened to the leather helmets? What is this forward pass I've heard so much about? Also, I wonder if Rick Jones could get me a beer? I could sure go for a beer. Mm, beer! Bucky used to get me a beer. God do I miss Bucky. I long to see him again. I wonder if that could in any way be construed as strange?*
Rick Jones: Jeepers, why is Cap looking at me like that?
Ant Man: I predict that I will hit the Wasp at least five times if I lose money on the Colts!
Wasp:Â God I hope the Colts win. Stupid Jim Shooter!
*Other people who have read Avengers #4 thought that Cap making Rick Jones the new Bucky was extremely creepy, right?