Brian
UNC is an awesome place to go to school - it has a perfect blend of academic quality and extracurricular opportunities. It has both big-name NCAA Sports as well as smaller club teams, and there is a seemingly unlimited number of student groups to get involved with. Franklin Street is great for some quick shopping or dining, and the proximity to Southpoint is excellent as well. There is a ton of school pride, and there's always some sort of controversy on campus, which isn't necessarily a bad thing-it just proves that students are passionate.
Cindy
Best thing about UNC? Two words: Men's Basketball.
The biggest controversy to hit this campus in years was last year when the athletics department moved to end the Saturday morning, 6am bracelet line for basketball tickets in favor of an online lottery system. They practically had armed revolt on their hands, and "true fans" are still pissed that obtaining tickets is now a matter of luck rather than dedication.
Carolina is a pretty big school with a really vibrant array of student organizations, almost everyone's involved in at least one. You have to be, or you'll risk having no social life whatsoever. Most any group or sports team will occasionally host unofficial off-campus house parties for their members and friends - our school paper, the Daily Tar Heel has hosted some epic keg parties since I've been here, all of the clubs I'm in have done the same. Last year they passed laws making it more difficult to get a keg, so a lot of big house parties will opt for PJ instead, since high-proof grain alcohol like Everclear is still legal in NC and more easily obtained. Most of your first two or three years will be spent at house parties, unless you have a good fake or an older sibling that looks like you.
The most frustrating thing for me freshman year was not being allowed to have a car. They tell you how great the bus system is, but without a car, grocery (or any other) shopping is practically impossible. It doesn't get much easier after freshman year either - there's practically no parking on campus. A lot of people overcome this by paying friends off campus to park in their yard or driveway. I actually paid the rabbi to let me park at the Chabad house for two years and was much happier. Many sophmores, juniors, and seniors move off campus for just this reason.