If one of your main concerns is function over fashion, look into an Eclipse deck. Seeing as how they are the makers of (most) OEM decks, the menu is set closely resembles that of the stock deck. Like the stock deck you just push the biggest button on the deck(volume dial) to scroll through the main settings and turn it to adjust. How much more intuitive can that be!?
Like you, I too hate the flashy, overly complicated decks on todays mkt. Should my current Eclipse deck fail, I'm most likely gonna get another Eclipse based on the fact that it's simple looking, simple to use and is manufactured with it's task in mind.
I will warn you, their prices don't look too attractive though when you compare them to the other brands. Checkout their site for more info
http://www.eclipse-web.com/index_cd.html