"FYI, Frontera takes only a limited number of reservations--it's mainly first come, first served--so you could be in for a long wait if you show up at 7:30 or 8 pm on a Friday. If you're unable to get reservations, you might want to opt for his other restaurant, Topolobampo, which is in the same building."
Good advice. If the weather's nice and it's a touristy weekend, expect a 2 hour wait for Frontera. Topolobampo, although more expensive, might logistically be a lot easier.
For Deep Dish, there are a few styles:
Pizzeria Uno, Due, Gino's East, & Lou Malnati's are all pretty similar, but my least favorite Deep Dish.
Then comes the crystallized cheese Deep Dish: Burt's is great, but if you're in for only a couple days, it's a bitch to drive to Morton Grove. You can always go to Pequod's on Clybourn if this tempts you.
My favorite, however, will always be Art of Pizza (on Ashland). Their stuffed crust pizza is truly one of the best things I've ever tasted. Make sure you get stuffed.