Bugatti Veyton (above): 986 horsepower engine, W-shaped, 16-cylinder engine
Owners: Ralph Lauren; Tom Cruise; Simon Cowell (American Idol judge); Ben Brooke (Hedge-fund manager, owns two) (Source: Wikipedia)
http://en.wikipedia.org/wiki/Bugatti_Veyron
Mercedes McClaren (above): 627 horsepower, V-12 engine
Pronounced (KOON-is-egg)
Koeingsegg CCR (above): 802 horsepower, V-8 engine.
My personal preferences would be for the Mercedes McClaren, and the Koenigsegg CCX (last photo). How about you?