Amazon.com: Pioneer AVH-X5500BHS Multimedia DVD Receiver with 7" Motorized Touchscreen Display: Car Electronics
This is my winner when my tax return gets here. this is normally $500, here it's $380.
It also have the parking brake override bypass kit available for purchase so your passenger can watch DVD's while you drive. This is the newest line just released last month.
Make sure you read the "what about bose" thread in the sticky if you have the bose system. It is very enlightening.