Ok guys here's the scoop.. I've lived in Tucson 20-some years, went to HS and am a U of A grad. Needless to say I know this place a little too well.
As mentioned, there are some bad places (like every city). What most U of A people don't realize is that there are some stunningly beautiful places too (the views and area). The best area to live in that's reasonable to campus is the La Paloma area. The main apartment complex in this area is The Legends. The Legends is 15 minutes from school, in a completely crime free area, high end shopping/restaurants (Flemmings, Coach, Cole Haan, etc) surrounded by million dollar plus homes, and next to the luxury Westin La Paloma resort. This is where I would live if I had to pick an apartment for school.
My second choice would be Summerlin Villas located on Camp Lowell and Swan. This neighborhood isn't as good as the Legends, but the area is quite good and new and the apartments are very nice. You're looking at about 10 minutes from campus.
The area on River between Campbell and First is a very nice area with PF Changs, my favorite place.
The problem is the area is very well known by undergrads, and you can run into problems with noisy neighbors. The apartments in that area are also becoming old, so be a little more cautious.
If you don't mind a further drive, the Greens and and other apartments next to Lowes Ventana Canyon are great too. Looking at a 20-25 minute drive there.
Good luck everyone at Arizona! I met with Dean Holpert many times about my law school decision, and I can tell you there are some great and genuine people there! I'm going to USD just so I can experience another area, but I wish I could bring the U of A law school out there with me.