I think green7 made some excellent points, especially about Athens. Remember that there are only 6 football weekends a year; that's not too long to put up with the chaos. But honestly, it is not required that you be fanatical about football or the Greek system to "fit in" here. Although I wasn't spending every Friday and Saturday night in my apartment, I was also not the party-type of person, but found a lot of fun things to do. We have a wonderful gym here (if that's your thing) UGA may not be as racially diverse as some schools, but I think that it is very ideologically diverse. You will find people here that you can call your friends. I promise
To answer your question about baseball, this year hasn't been the best for us. Last year, we did make it to the College World Series, though. The softball team is pretty good year-after-year.
Good luck deciding between UNC and UGA. They are both great schools, so you are definitely in a win-win situation.