Mainly, football (soccer...) is that... "bomb", the number one sport...
Other than that, or at least here, there isn't really a number two sport. It would depend on the communities and the person is searching, me, in example, am inside a tennis community, so, around me, tennis is famous... Or something like that... >_>
But now that I think of it, I guess basketball is the "number two" sport around here...