TCP

I have many more suggestions of you're going to other neighborhoods, too.

We'll mainly be up in the Loop, but I definitely want to get up to Wicker Park and Lincoln Square if time will permit. I'm also going to Winnetka one evening to see a certain noteworthy Chicago-area songwriter perform in someone's house. 

Frontera Grill also has really good Tex- Mex and margaritas. It's downtown near everything at  445 North Clark Street.

I haven't really been out eating in Lincoln Park or Wicker Park. I tend to be downtown or in further-flung neighborhoods like Logan Square or Ravenswood. If you're heading north, I suggest you try Big Jones in Andersonville at 5347 N Clark St. It features Southern Coastal dishes and serves a phenomenal brunch, but not really close to downtown.  I hear it's great for dinner, too.  

If you're going to Winnetka, might as well just go a bit further north and visit Milwaukee and have some brats and Schlitz beer.

If you can find a Culver's in Chicago, get a butterburger and fried cheese curds. They're a Wisconsin fast food chain and serve fucking outrageously good burgers for fast food. You couldn't find them in Chicago until the past few months, my Chicago friends tell me.