Bonnycastle is really nice with the Castle in the basement, great for late night food, especially the Cyclops Burger (like a Gus burger, but better).
Dorms at UVA aren't generally huge for parties, mainly since lots of the RAs are very strict about drinking in dorms. If you keep it quiet, then you're generally safe, but the sounds of pong and lots of people in a room are a dead giveaway. The big downside of old dorms compared to new dorms is that there are no closet doors to take off and use as a pong table
Historically, I'd say the majority of people in old dorms were those who joined the greek system, but since we didn't get to pick Alderman or McCormick last year, things were all jumbled up.