A 1990-1994 Subaru Legacy would be a great car. They get great gas milage, and most of them are AWD. Most are under $5,000 and should run a long time. They are easy to work on, and parts aren't that expensive. The only major problem with these cars can be the Automatic transmissions.
My brother's 1990 has been a great car, and he has 185,000 miles. In the last week or so he has been having some engine problems, but I think it might be due to him driving it VERY hard all the time. Other than that, it has needed very little.