Rainforest Cafe?!?!?! NOOOOOOOOOO!
It used to drive me crazy when my friends would come into town and want to eat at a chain restaurant. You're in a city with all kinds of AMAZING foods and you want something you can get anywhere?
Ok off my soapbox now

here's my recommendations:
Restaurants:
Bongo Room for breakfast.
Kuma's for burgers.
Hot Doug's for hot dogs.
Big Star for tacos.
Piece for pizza.
Portillos for fast food, get the chocolate cake.
Chop House or Gibson's for expensive steak dinner.
Those are my favorite places (besides Hot Dougs I've never been there, I just know it's good, be prepared to wait an hour or more at Kuma's or Hot Dougs) check out yelp to confirm my good taste

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Expect to wait at least an hour for Bongo Room, Kuma's, Big Star & Piece. I'll also say that they're pretty much worth it with the exception of Big Star which I find pretty overrated. The but the location is great!
For a zoo, I would go to Lincoln Park for convenience unless you are driving then I would pick Brookfield.
Stay in the city, hit Lincoln Park Zoo. Its free, its convenient, you don't have to plan your whole day around it. You can pop in for a couple hours. While you are there you HAVE to go to the Caldwell Lilly Pool. Most people don't even know its there and it is a serene hidden gem.
http://www.explorechicago.org/city/...tions/park_district/alfred_caldwell_lily.html
For drinks:
If you are into punk/rock music I love Delilah's on Lincoln

If you want to get all dolled up and go to some place unique I recommend the Violet Hour, an old speakeasy in Wicker Park (where Piece and Big Star are), it's pretty on the inside and the drinks are pretty freaking tasty! It has no signs or windows so it can be tricky to find, it has just a light on the outside of the building signaling if its open or not.
Yes for Delilah's for the music (you can check out the DJ schedule before you go. But the crowd and be quite a bit older.
Violet Hour is incredible. Great atmosphere, delicious drinks. The downside is the wait can be very long and the drinks are pricey. Like $16 each last time I was there.
A lot of the younger crowd can be found at the local VFW, believe it or not. AND they have karaoke! Unlike every other Chicago bar, they do allow smoking.
http://www.yelp.com/biz/chicago-blackhawk-vfw-post-7975-chicago-2
Unlike every other Chicago bar, they do allow smoking.
I would skip Navy Pier for sure its beyond lame and not worth any of your time.
I wouldn't plan a day around Navy Pier, but I do love a once a summer ride on the swings and the Ferris Wheel. Navy Pier is also a good transport hub as lots of lines start/end there. DO YOURSELF A FAVOR and stay away from the "free" trolleys. You'll pay dearly with your time. Get a CTA pass.
I named my own price on priceline on my inlaws hotel last summer and got a great deal for the W but not included of course was the $50 or $55 parking per day charge! (just another tip)
I've had great luck on Priceline/Hotwire. Just as long as there isn't a convention/festival weekend.
If you think you'll be in the Wicker Park area, look into Two Urns B&B (my friends stay there every time and love it) or The Wicker Park Inn. Consider the amount you'll save on parking fees (as ChiCat stated above) and taxis.
A few years ago we took an architecture tour along the river - well worth the time and it was really inexpensive.
The Chicago Architecture Foundation has an amazing amount of tours by boat, bike, el, walking, etc. for a fair price. So many options!!
You have to go eat at the Rick Bayliss restaurant XOCO.
http://www.rickbayless.com/restaurants/xoco.html The food was awesome! If you are walking around, State street is pretty impressive. There are things there like the Chicago theater and the new state of the art Walgreens. Navy Pier does have shops but nothing you can't find cheaper elsewhere. We bought all our souvie shirts at Walgreens.
XOCO is a MUST! Incredibly delicious and really fairly (even cheaply) priced!! So much value!
Speaking of stopping at a Walgreens, the Walgreens at North/Milwaukee/Damen is even better. In a converted bank from the 1920s, take trip to the lower level to the "Vitamin Vault" (inside the real old bank vault, with the door still there and everything!)
Anyone know of a firehouse with freindly firefighters?
I think every firehouse has friendly firefighters, and most seem to be sitting outside in the summer. Walk by any one of them, ask a question, and see who you meet. The ones in our neighborhood are always offering to let my son get his picture taken, touch the truck, etc.
Once again, I wouldn't plan an entire day around this but,
where the the Chicago fire started, just south of the loop, is the training center and sometimes you get lucky and see training.
http://www.time.com/time/travel/cityguide/article/0,31489,1846254_1846157_1845971,00.html
I don't recommend commuting in from the suburbs if you are planning on doing any real partying that involves drinking. You don't want to be trying to negotiate unfamiliar commuter train routes/schedules late at night with a buzz on. Stay where you can afford to cab it back from the clubs.
YES!
If your taking public transport stop at Navy Pier. Its free to walk around, have a stained glass museum sort of (free)
I forgot to mention the stained glass at Navy Pier. It is amazing and often overlooked. Grab a beer in the beer garden and stroll through.
I second the suggestion of eating at XOCO. The food there was fantastic. )
THIRD!