Here's my personal view of the programs:
first, all are really quite strong programs. there's widespread agreement in the em community here in chicago of that fact. there are positives and negatives to all of them, obviously, but all will offer a great education and experience.
Christ
Widely thought to be the strongest program. More selective to get interviews (USMLE > 230s or so), residents seem very happy, nice facility, great trauma experience (many other residents come to christ or cook for their trauma), in my mind weaker off-service rotations (ie medicine).
It's a one hospital system; you're at Christ for three years. I see this as a weakness, but others really like it. great ultrasound
UIC
Strong program, with very nice faculty and great residents. Strong off-service rotations. Three hospital system; one inner-city like community hospital which offers great experience. weaker trauma. weaker ultrasound.
U of Chicago
Very busy ER at main site; three hospital system as well, one suburban trauma center, one knife & gun inner city, and U Chciago, which is great in that it gets odd transplant patients along with the poor underserved local community. Good group of people, very strong off service rotations (except surgery), bad commuting. Good ultrasound experience. FLIGHT experience is great; 2nd years are flight docs. Also bad; that means that when the 2nd year is flying, everyone else has to clean up the messes. Quite a bit of scut, from what I found (I rotated). Pushing patients to Xray, etc. Not at the suburban location, however!
Cook
Not much firsthand knowledge. I wasn't interested because I'm not into scut, and because it's a PGY 2-4 program.. They get a great education.
Res
Very benign program. Best ultrasound in the city; they stole Christs' fellow. Lousy off-service rotations (my impression, not firsthand). Decent group of residents. Two hospital system, both are suburban, so not too much mix. A newer program, didn't fill last year. I liked it, but didn't rank it too high (not too low either!)
Northwestern
PGY 1-4. Widely thought of as the weakest Chicago program, but I see that as changing. I was impressed at my interview, but still didn't rank it highly because I don't think it's quite there yet. New PD is really great, and concerned about quality of faculty. Nice facility, great off-service, ?Ultrasound (i forget). Lots of ICU months (I think 9). Makes for a better physician, but why not get double boarded in IM/EM? they used to in this program, and that's one of the reasons for the heavy ICU time. Definite up-and-coming.
UI Peoria
Very nice place, but in Peoria, about 2 hours out of Chicago. Facility worn down, faculty very nice and friendly, residents seemed more family-oriented, very rural feel. Not for city folk.
That's my personal opinion. I think the best programs in the city are Christ, UIC, U Chicago. Res is close, and then Northwestern. Others will have vastly different opinions based on their own interests, and what they find important in an EM residency.
Suggestion: do a rotation or two in an ED where you'll apply. Get to know it.
Best of luck!
PS it really is neat to live here. Chicago is one of the best cities in the nation to live in. BUT ITS 50 DEGREES TODAY, AND IT'S JUNE!