I love Southwest.
I definitely prefer Southwest to United and American Airlines if you're flying to San Jose, Las Vegas, Los Angeles, Albuquerque, etc.
- Bags fly free
- Boarding pass printing/check-in kiosks for fast, easy, on-the-go service
- Friendly/funny flight attendants
- Comfortable seating
- First come, first serve seating
Just be sure to check-in as soon as it's 24 hours prior to your flight so you get first dibs on seating/overhead compartment carry-on space.