Park and Jet is the cheapest. I want to say it is $7-$8 a day with a crew ID, but they do tack on a $4-$5 city tax fee. I ended up in Preflight $90 per/mo and a one time $30 fee for the prox card. Also you can park indoors. The shuttle service seemed to be a bit better. Also depends on where your driving in from. Park and Jet is West of the airport, Preflight is over by the taxi parking lot so it takes a bit longer to drive there.