Alright, working in car audio for a while, I've got a Kenwood DDX 318. It's non bluetooth (didn't need it) and it's non Navigation (I've got a smartphone for that)
I love Kenwood Touch screens for a few reasons, one being that Kenwood's head units offer the best tuning of audio that I've seen. (Like a mini crossover in there) And It's got a volume knob, so you don't have to look down to turn the volume down. It's incredibly user friendly, and easy to figure, and it's Kenwood. In my opinion, they make the best/most reliable headunits for the price. If you wanna go expensive, Alpine makes a few, they're nice, but I don't feel they're worth the price.