As someone who straddles the liberal activist/fraternity member divide, I can say with confidence that no one social group in Athens is so oppresive that you can't escape it. True, about 18% of UGA's undergraduate population is in a Greek-letter organization, but Athens is a really diverse community to be as small as it is (around 100,000 permanent residents). Athens has a thriving arts/music/culture scene, and there are a variety of cultural events (especially the Human Rights festival) and community events (especially the Twilight Criterium, a nighttime bicycle race through downtown Athens) that really help make Athens a great place to live for all kinds of people. UGA has an incredible array of large-school research advantages but it hasn't changed Athens' small town feel. At the risk of sounding cliche`, Athens really does have something for everybody.
I earned a B.S. in Psychology and an M.A. in Religion here, and after 7 years I'm sad to leave. Regarding places to live, there are a number of complexes which are difficult to find online, but easy to find by driving around town. My recommendation to anybody who is moving here is to come here for a day or two and just drive around. My favorite area to live is just West of the dorms, off Bloomfield. It's a quieter area with houses and smaller apartment complexes, and the UGA bus goes down Milledge Ave. so a bus stop for the campus bus is never more than a block or two away. I enjoy it because I refuse to pay for a parking pass, and Athens is a *very* bike/walking/public transportation friendly place.
I agree with the post that advised against North Ave. and Riverbend Rd. In my experience, any kind of gated community that you can find online (the Woodlands, the Retreat, the Reserve, Abbey West, etc) are all going to be full of rich white undergrads from Atlanta suburbs. As a graduate student, your best bet is to find the smaller complexes around campus (Dearing Gardens, Bloomfield Terrace, The Springdale, Mi Casa, etc). Also, some of the older areas of town (off Hancock Ave., Reese St., and other cross streets between Milledge, Broad, and Prince Ave.) are being rejuvenated. A number of older, smaller houses are being renovated in that "craftsman" style that seems to be so popular.
Finding great housing in Athens is relatively easy, but the easiest way to find it by far is to come here and look around campus, particularly west of the dorms and right around Five Points (where Lumpkin St. and Milledge Ave. meet).
Congratulations to anybody who's been admitted to UGA for Fall '08! You'll love it!