Don't bother staying for more than 3-4 days - There's not much there that will take you longer to see and do. You absolutely MUST do the Alcatraz Tour, though. Evening if possible. Amazing - you'll never forget it.
Laguna Beach, California. Felt like I'd lived there in a previous life. I felt so at home! Not a glamorous place really, but I just loved it...
Second to that - New York, but only in Winter.