I don't really follow sports but if I had to root for someone then Lithuanian national basketball team it is then. As for football (yes you call it soccer in some places, but really... its football.) i don't really see how it is fun to watch people chase ball for hours without anything happening.
Sometimes I watch Tenis, motor cycling, like the ones that make tricks, both motorcycles and bikes, skatebords and ice skating not something i watch 100 and follow but those are things Iwatch from time to time