I lived there for 8 months 3 years ago.
Great place.
I'm sure you know, but its very cultured, with tons of art galleries, and very good restaurants. Very cool downtown area called "the plaza". Great place for hiking and skiing as well.
Not too much nightlife for twentysomethings, but still has a bunch of cool bars.
There are also 3 casinos w/in 30 minutes drive if that floats your boat.
The people for the most part are laid back. Lots of rich folk who have their second homes, and it seems like the rest of the people are either artists or work in the service industry.
Let me know if you have more specific questions.