i currently own a pioneer 7000r, a sweed head unit with a flip down face, a much better 45x4 amp inside than sony (from past experience) and i ordered for like 20 or 30 bucks, an aux adapter that plugs into the cd changer port..also..a cool feature is that you can change what you want the aux sourse to say (for example, mine is "mp3").
pioneer, clarion, and kenwood rock
I bought the kenwood excelon krc-x657.
It has cd controler, they make a adapter (ca-c1ax) for rca input. There is a nice kenwood excelon skin for winamp at there site.
Ive got an Aiwa head unit and I think it's great. I do agree that the front input doesn't like as neat, there are ways to get around that and still keep it looking ok. When I bought the unti it was the best priced for features and quality among heads with Aux input (right next to Panasonic). They only real thing that I can say about it thats negative is that its slightly prone to stoplight syndrome. Where you'll stop and there will be a very small area where FM recpetion is bad. Problem can usually be solved by inching up a little. One head unit you could look into is Blaupunkt. Especially if you want crystal clear FM reception. Moat of there units also have rear inputs or you can get an adapter to have rear inputs. One other thing about the Aiwa units...the 2000 models...the have a 'unique' styling that I just dont like. The 99 and under models have a very nice clean interface.