Whether you're due to go out and hit some bars or not, you can simply never go wrong with Everything But the Girl's
Temperamental...
http://www.youtube.com/watch?v=tCkOlvZQiDs
For chilling out and staying in, there's always Sonny Rollins'
Saxophone Colossus...
Sonny Rollins - Strode Rode - from Saxophone Colossus - YouTube
Ambient music's great as well. Any Biosphere, Popol Vuh, Global Communication, Bohren and der Club Of Gore or whatever always goes down well mit me.