Hm. I've lived here for 10+ years, and I agree with some of what's been posted and disagree with other stuff. Thoughts, in random order:
Oh, and I can be rather opinionated. You've been warned.
Skip deep dish pizza. It's just a giant cheese bomb. A very interesting alternative is Chicago Pizza and Oven Grinder, on North Clark. Plus it's close to Old Town and Lincoln Park, Yuppie Central.
The Art Institute is pretty much fantastic, and it's on Millenium Park, which is, too. The Museum of Contemporary Art is just ok. Much more style than substance.
Tru has gone downhill quite a bit, and isn't even LEY's flagship now. That would be L2O. Trotter's is an institution, although it's not what it was 10-15 years ago. I would suggest Blackbird on West Randolph (although it can be loud). If you want steak, the Capital Grille on St. Clair destroys everywhere else in town for food. Gibson's can't be beat for scene, though. (And yes, Chicago is the current tops for food in the US, imo.)
The architectural boat tours are great.
I have no idea what it is that people here love so much about Irish bars, but you don't need to plan on hitting a specific one. You'll see one about every 25 feet.
Drinks at the top of the Hancock is cool.
There's some great shopping on Oak St. and Michigan Ave., of course. If you do that, have tea at the Drake on Michigan. Very classy.
Wrigley is pretty great, but skip the bleachers unless you just need an excuse to get drunk on beer in plastic cups.
Time for work. Maybe more later.