I got a 2005 LS Cobalt as a lease while in college. After 34,645 miles, I have had no problems with the car. The only service the car has required are regular oil changes, seasonal maintenance, tire rotation, and yearly inspection. I have only had one issue - on occasion, CDs will stick in the player and it will return an error. They usually eject after pressing the button several times or turning the radio on and off. All in all a great car for the money. Excellent gas mileage, does well on road trips, has low road noise, and the computer gages are great for tracking gas mileage.
Spoiler, computer gauges, mileage
Jazz up the interior a bit, and provide a more comfortable bucket seats.