Why not both?

For me, this is rather easy. I love the color blue. Always have, always will. Heck, most of my avatars on games and websites are blue. Not only that, but the blue teams tend to have the best overall character.

Here's why I think that:

TF2: BLU pushes an explosive payload up a hill, through constant RED assault.

That takes some serious balls to do that.
Red team just spawn camps and spams the door with sticky bombs like a bunch of pansies.
And in the "Meet the" Videos, RED team always treats BLU team like shit. Especially in "Meet the Spy"

RvB: Blue team has the best Character In the whole of Red vs blue. MICHAEL J FUCKING CABOOSE!!!