American sports - which one to watch live?

[Uppy89]

I appreciate this is a very subjective question but I am travelling to Chicago in May and would love to catch some American sport whilst over there but what one do people recommend as a tourist and American sport rookie? In this country, I have a season ticket at the football and watch probably 10 rugby union matches a season live so that is the sort of thing I enjoy.

I understand the basics of all of them so was looking more at the atmosphere and general viewing experience...

It looks like the Bulls for Basketball, Cubs or White Sox for Baseball or Bears for American Football so any thoughts and experiences on which one to go for would be appreciated.