Toyota Corolla ( very spacious, good center of gravity and good engine )

Honda Civic ( reliable engine )

Mazda 3 ( don't know if the hatchback 5 door is under 15 k but better than the 4 door trim )

Suzuki Sx4 ( stylish, also reliable and economical )

Chevy cobalt ( good power train, premium sound system )

Pontiac Vibe and Scion xb are on 15k.. These are also good cars..

I would go with mazda 3 or the corolla