O's and Ravens here.
I was a Vikings fan for years since they were my team before the Ravens came into town. I always rooted for the Ravens, but took until the post-Favre era before I officially switched.
I've occasionally rooted for the Wizards/Bullets, but they've never been my favorite. I tried getting into both Terps b-ball and Caps, but I'm just not into college sports or hockey. Nothing against them, they just never stuck for me.