I don't claim to have the knowledge that Sweet Willie does, but so you're not totally shut out here, a few suggestions:

Rush Street (aka "the viagra triangle"), while somewhat touristy, has a lot of atmosphere and is definitely a scene. I'd choose Gibson's if you want a lively place that's one of Chicago's better steakhouses.

Also, some of the sushi places like Japonais and Sushi Samba could be pretty fun.

You might also try metromix.com and citysearch.com for some ideas.