Cervelo R3
This, my friends, is the perfect road bike. It is lightweight, but stiff. Stiff, but comfortable. Comfortable, but fast. Fast, but stable. Stable, but lightweight... Oh, did I mention it's lightweight? Ready to ride with computer, pedals, bottle cages, and an under-seat tool-pack containing basic tools, CO2 inflator, and spare tube, mine weighs barely 17 pounds.
Ditch the tool-pack and throw on a good tubular wheelset, and it's below the UCI minimum weight limit...
Of course your definition of perfection may vary: but this definition ---and this bike--- is mine.