Look at some Hyundai's or Suzuki's. They usually have good warranties, and they are dependable and fun to drive. Personally, I only buy used cars that are 2 years old and still have a warranty left, but this is up to you.
Your car keys have been stolen? Who steals car keys? It sounds a lot more likely that you stole the car, and that's why you don't have the keys!
Do you have the title? If not, you're in trouble.