This is the One. Sorry for the lame statement but for the most part, it's true. The One:1 is the very first car to ever have 1hp per kg. It boasts a 1360hp twin turbo V8; the usual thing with Koenigsegg. It's said that it has a top speed of 270mph (very, very fast).
This is an open discussion, so feel free to say anything about this legendary car.