I purchased this vehicle Dec '05 with 4 miles on it. I cannot say enough about the '06 Cobalt. I truly love it. Its handling, the way it looks, warranties, etc. It was the best purchase I have ever made. And talk about great fuel economy. My household has 2 people driving this 1 vehicle and we still only fill up 1x/wk for about $25.00. The insurance is awesome too. I recommend this vehicle to everyone!
If I had to narrow it down I would say the auto lights and the manual windows.