Here's a good starting point. The HU has built MP3/WMA support, Satellite radio control, and it has 6-channel digital time correction control.
The 6-channel time control allows you to adjust for the different distances from each speaker to the listening postion. Essentially it allows for you to create a "perfect sweat spot" where all the sound will/can reach a certain point at the same time. This will usually make your system both louder(due to the perfect phase of the waves), and sound better.
I like the built in satellite radio control because it doesn't require you to have the tuner in site, which you normally do. It allows you to change the station directly through the HU.
Here's a Pioneer HU with built in DVD support, but it doens't have as many features:
http://www.cbrstereo.com/index...D=577
It does have duel video outputs for multiple monitors though. WHich is nice. And it has the option of Dual Zone. WHich means you can play two seperate sources at the same time, one in front, one in back.
What else do you need? Speakers? AMp(s)? What is your goal?