Which one and why? I got into CS in the college of engineering for both. I will pay in-state tuition for UCLA and out of state for UIUC. I am aware that UIUC computer science is ranked higher, but I have learned time and time again that rankings are misleading.
Also, I am mostly interested in entrepreneurship/startups.
The amount saved by choosing the in-state option will be a nice reserve if you want to start up a company, since a new company may have to do some work (at least proof of concept) before getting either revenue or funding.
They are peers. Go with UCLA.