1. SAN FRANCISCO BAY AREA: $10/NIGHT.
For about the cost of a movie ticket, you can get an entire apartment to yourself in Oakland, Calif. This one-bedroom suits a solo visitor or a couple and has a full kitchen, washer/dryer, and wireless Internet. It's a quick walk to the nearest subway station and a 20-minute ride to San Francisco. If you're into wine, Napa Valley is a 90-minute drive.