What are the best universities in Illinois if you want to major in pre-med? And how hard is it to get accepted into them? If you already are in/were in one, what were your ACT/SAT scores and your GPA?
I'm in the same boat as you right now, and it is really a personal choice.
Have a look at the state schools, because here in Illinois they are vastly under rated and the tuition is pretty low for in-staters. I am currently looking at Eastern Illinois, because I will be a legacy student and I have found it to be very nice. Small classes for the most part, and from what I have heard there is plenty of individual attention from professors. Also the campus is pretty modern. It even has a Alpha Epsilon Delta chapter, the only state school other than U of I to have one. As for acceptance, it is not terribly hard...if I were you I would shoot for a 25 and up on the ACT? Not sure.
On the other hand, U of I is a big, well-funded institution, but has serious draw backs for the pre med. It is also more selective, look for a 29-32 to get in. On the up side, you have many great research opportunities. But, do you want to be learning the most challenging concepts of science in a room of over 150 students being lead by a someone other than a full time professor? Are you okay with a large college scene with many distractions? Do you want a personal relationship with professors? This is harder to come by with bigger schools.
On the other hand, you have your private schools. I don't know a lot about them, because quite frankly, they never seemed to be an option for me. I say pick a state school, study your butt off and build good relationships with professors. You will save a pretty penny over a small private school.