If fun to drive isn't an issue, the Prius is going to be your best bet. It gets incredible MPG and is one of the (if not the) most reliable cars built. Toyota has sold a ton of them so parts are easily available and mechanics wont be unfamiliar with them. The power and handling, however, are never going to be anything better than just adequate. Anyone saying they're dangerous is just being hyperbolic, but they're not built to be sports cars by any means.
That said, they do ride quite well, they're pretty comfortable, and the newer models are pretty quiet even at speed.
If you want something that drives a little nicer, get a Mazda3. The 2.0 gets 40MPG on the highway and they handle remarkably well. They're not fast, but unless your commute involves a lap of the Nurburgring you'll be fine.
Originally Posted by MParr
If you could find a low mileage used VW Jetta TDI (diesel), that should meet your requirements.
Except for the reliability and ease of repair issues, which the TDI isn't to either one.