I've always been a big fan of Southwest Airlines, previously living in Locust Point I was ten minutes from BWI Airport. For Southwest, BWI was one of their largest airports and with the new terminal it's even better.
Faster security lines, better food (if that's possible at an airport).
DING! Their windows applet that delivers deals to your computer multiple times per day.
They've built an excellent web experience (at least once they had fixed the problem of losing your reservation settings when you hit the back button). You quickly see when you earn flights, etc.
Normally they send cards during important holidays, like your birthday.
Today I received an Flash email card wishing me a Happy Thanksgiving (click here to check it out). I'm not a designer, but I thought it was well put together.
Enjoy yourself and start flying Southwest to get your own.