Blue Hen Shuttle has been my friend for two years. This airport shuttle service caters to local Delawareans who need to get to PHL (or BWI) and don't feel like being ripped off by Delaware Express. Mention you're a student and they'll give you more of a discount. This is a ma-and-pa operation, but they offer door-to-door service and will wait for incoming passengers in baggage claim. It doesn't have the same professional feel that DExpress has, but if you just need a ride, this is a reliable way to go. Call ahead!