I personally like pioneer and kenwood. Alpines sound good, but I haven't had much luck reliability wise with them 1999-2003 vintage, $200-400 range. Mostly broken/sticking buttons and or problems with the connectors and/or motorization of the face. I stay away from anything motorized now, and prefer the cd slot be accessible without the face moving at all to help avoid contact connector issues.

I bought my pioneer D3 mostly because it filled the dash adapter opening, and provided a nice screen to scroll through my iPod with. I use the navi on trips, but have never played a video in the almost 2yrs I've had it.

Yes, im using a pioneer head unit, Kenwood 800w amp, and 2 10" kicker speakers. Sounds great.