What kind of car should I buy?

Since my Jeep is on its deathbed, I'm looking to trade it in with the Cash for Clunkers program. If I don't do that, it wont make much of a difference for what I'm l ooking to buy - A car with good gas mileage, new OR used (oldest ~2004), minimal miles on it, with a price tag of around 15,000. Note: Hate the Ford Focus and do not want a Scion or some tiny two door. What's the best bang for my buck?