Too many posts for me to agree with or knock down the suggestions. It is kind of a personal question. Do you like 'Gaudy Looking' decks like the alpine shown here? Its a great deck, but sometimes you want something to match your interior better, not dominate everything and overpower the instrument cluster. Refinement and features. Does it need to be an MP3 player or not?
I say you can have a deck like pioneer where they have a bzillion f***in buttons for everything, which are cryptic to comprehend and use, clarion which is only a bit better (and both of which are bulletproof by the way), but yet leave something significant out.
I Choose eclipse as the best High-End head units. Ive owned or bought for friends and installed all of the above mentioned decks at one time, but I have only repeat bought clarion, pioneer, and eclipse. The first two are great products and very reliable overall. The eclipse outdoes them in its esthetic refinement, button placement, look and sound quality. I had an eclipse 5303 which was an awesome deck and the first eclipse with the rotary knob. I got offered a great price for it so I used the money to buy the currently new Pioneer 8000 something or other with the organic display and changer. It had every fricking thing, crossovers, FIE, organic display, etc.
ONE little thing drove me absolutely nuts. WHenever I put my cd player on the power antenna would stay up. My eclipse would lower the antenna with the cd on and raise it only with the radio on. It was great since I like to drive really fast sometimes with music on and I didn't want wind resistance to bend my antenna. I would just pop on the cd at speeds above 90mph.
The other thing was I didn't use any of the other crap on the deck. The high end eclipse has no extra junk, it doesn't even have speaker wires on it. You have to use amps with it. With a dialed in system of amps and crossovers you have no use for all the gimicks. Thats it.
Thats my 50 cents worth, and here is a bad picture of my 1.5year old 5506 eclipse head unit.
warmonger (I know it sounded pompous, sorry)