Not sure you can get one perfect bike for all of it. I still want drops for the weekend, despite my flat bar obsession for commuting.

Ultimate bike, Ultegra (or even Dura Ace) bits on the drivetrain. Flat bars, with the requisite shifters and levers. Carbon frame (oh yeah, I already have it, realize you don't want it, but I really like the carbon a lot). Road gear range on the cassette, and a double up front (triples are useless to me). Discs would be pretty awesome, actually beyond awesome.

My 2 cents.