Money no object = Macintosh, absolutely bullet proof! I've never owned, but have friends who do and won't shut the Phuk up about how awesome they are. I have heard and agree that they are sweet, but I think IMHO, they are beyond the point of diminishing return for the $$$
spendy but not OTT = a/d/s & Nakamichi, both are very solid, detailed, clean, and capable. I had an a/d/s amp in a preivios car and loved them, they were driving MBQ's. Now I have a pair of Nak's driving a/d/s speakers. For me it is the perfect combination. The amps are not colored at all, and the speakers offer absolute clarity without being bright like the MBQ's were.
ON a budget = Sony or Alpine, never owned them, but have heard only good things from others
Hope this helps,
Mark