I like the Pioneer 106s I just bought.
Slot load, 16x DVD, ata/66.
Grabbed it off ebay for like $25 shipped. I plan on getting a USB to IDE adaptor to wire it from my dash to my trunk with just a USB cable.
Dunno bout power consumption yet, I havent hooked it up yet.... I'm waiting on my screen from Digital WW to put it all together :-P