For me the sun has been very good short term, but is the reason I have so many problems in the Fall, Winter, and Spring. I'm out in the sun 10 hrs a day for three months and I guess once Fall starts things take off.
I've noticed that the sun makes my skin look better. Just be careful though. I wouldn't spend hours in a tanning bed (or in the natural sun) because of the possibility of skin cancer and stuff. Also if you have very white skin most places will advise you not to get tans. But for me, I find a tan makes my skin look healthier and clearer.