The latest Pioneer D'Din release featuring Dual Phone Bluetooth, iPod control & charge via either of the Dual USB inputs, SPOTIFY Link allowing control of your spotify App on your smartphone & 3 pairs of RCA output!
Sony WX900BT 220W Double DIN CD Receiver with Bluetooth
Kapture KPT-600 In-Car HD DVR with Crash/Sports Cam and Accessories $78.40
I believe any modern car audio system should at a minimum have an MP3 player, Bluetooth & GPS and most of all a decent radio tuner (an input for a reversing camera or the likes is also handy)
DVD players, TV tuners etc, are all pretty cool features, but I've found i havent used them really… you can really only use them when the car is off, and then you need to deal with a flat battery… I've found portable dvd players have been more handy in this situation.