I'd say house, i'd rather drive a cruddy car back to my own pad than live with parents with a fancy car.
Plenty of my friends spend 90% of their wages on their cars, then come to my place and moan about how they want their own place. I've even got a couple of mates who rent because money that *could* have gone on a house went on cars instead.
It WILL take longer to save up for a car when you have your own place, but does it really matter that much?