I have the Alpine IVA-W203... It's a FANTASTIC deck if you have the money. I think it runs for about 1000 including GPS or about 700 dollars if you don't get the GPS. It has features, plays DVDs, GPS available, I-pod hookup... it's fully loaded and I love it. The picture is fantastic, the only thing you have to be careful of is glare in this car. It's hard to find a nice double din dvd player for 300 bucks though. Pioneer makes some pretty good ones that are a bit lower but your sacrificing quality and features.
If your going all out i recommend the IVA-W505.