Parlee Z5 stock
My dream bike is a Parlee Z5 — an all carbon fiber bike that can be built as a complete bike at around 13lbs. My current bike is not heavy at a little over 17lbs and bikes for racing have to weigh at a minimum 15lbs (thankfully I don't race). Shaving 2 to 4lbs off a bike would be really great though. I could also just eat less and lose some weight.
Anyway, for the build I'd go with the SRAM Red group with ENVE seat post, stem, and bar, Fizik seat, Look pedals, and TRP brakes. I'd also go with the Dura Ace 7850 50cm wheels because they're carbon wheels with an alloy braking surface, otherwise would go with Lightweight or ENVE clincher wheels.
If all goes well, maybe in 2012? I could use the time to think of a nice paint job, though will probably end up with something like the first picture above — a solid blue bike.
I'm in the camp of people believing that carbon fiber is the best material for road bikes. Carbon fiber just sucks up the bumpiness in roads that it makes for really comfortable riding. I've ridden maybe 10,000+ miles on my road bike and can't complain — stiff, durable, comfortable, just solid riding.