2nd year phd student here, I'd mostly echo Ikn's statements.
Can't agree with there being "no decent restaurants", though it's not really great. I really enjoy the cute downtown area adjacent to campus. If you have a car, the surrounding area has tons of great options, and of course being a train ride from manhattan or philly is awesome. good set of reviews:
http://www.cs.princeton.edu/~wayne/princeton.restaurants/
I went to a large state school for undergrad (aka total college town), and naturally the social scene at Princeton is wildly different (students are in the minority at town bars.) The social life is absolutely what you make of it, and what friends you make -- to a large extent. I (male) have had great success in the dating life (particularly if you extend your search outside of other grad students), and it's only natural that an event like speed dating at the grad college is going to get more male signups than female. The social divide between undergrads and grad students here is definitely unusual, and some people might find the relatively small population of grad students to be restrictive, but I personally don't mind it.
I do really like this place, but if you're looking for a grad school with a huge party scene, this isn't the place for you. But if you want a nice peaceful town/campus to live and work in for a few years, and prefer a smaller group of friends for dinner and drinks instead of massive ragers, this is a pretty great place.
Full disclosure: I live off campus. I have no idea what's going through the minds of people that show up here and want to live in what are effectively dorms.