In Dash DVD Review/Recomendation

Hello all, I curently have a Magnum SRT8, with a factory NAV head unit and Kicker system. I have updated the sub with a Kicker L7 and a 750.1, but the rest of the system is crap.

I wish to replace the factory head unit (and all of the speakers, add in another amp, but no help needed there), and install rear monitors. I use my car for business, and require NAV, Ipod, and DVD capability. I am aware that most of these are add on features with most manufacturers.

Here is the question, I have been floating around on here, but I really cannot estimate which may fit my requirements best. I have used Alpine head units in the past, and have quite liked them. I have also used a few Pioneer, they were hit and miss. Whom make the most reliable, most versatile, cearest video? most audio adjustable package?

Alpine? Clarion? Pioneer? JVC? Eclipse?

I am aware that this is usually an oppinion quaestion, but if it works for others, and it seems most common, then it must work.