I liked living at canterwood (eisenhower + arapahoe) more than close to campus. I got a nice, quiet apt, with a view of the front range, and it was still a quick drive to class - though i could've taken a bus. It had a decent little gym just outside my building too. I felt I got more bang for my buck being a few minutes outside of campus.
Downtown, near pearl st. is a total rip though. It's not worth the extra cost in my opinoin.
Edit: if you don't drive, you might prefer downtown. You can walk everywhere you need to go.