Im a prime man! 35mm, 50mm's, 90mm, 105, 135, 500.. (nikon though). The 50mm f1.8 is without a doubt the best couple of quid you will ever spend.....ever, ever, ever!!! ive got the f1.4 too but dont bother with it.
Imho kit lenses are vastly underrated and there is nowt wrong with your lenses...