My son and I were out looking at headunits for his Saturn yesterday and I really liked the Alpine line. He's looking to stay in a tight budget and the Alpine CDM7874 is $199 (cheaper on ebay) and has some great features for the price. There weren't too many other units we saw that were comparable in that price range.

Try Crutchfields website. There's a lot of great info on what will fit your vehicle and the installation kit you'll need.