I voted for Caucau...
But I think we need to narrow down the question so we know exactly what we are talking about..
Are we talking about athletic fastest, or about rugby fastest?
By athletic fastest i mean they can run 100m the fastest, and by rugby fastest i mean they can cover 25m faster than anyone else.. cuz if you can cover that first 25m with a ball in hand faster than anyone else then the rest dont matter really, you will be very hard to run down..
and for that reason i chose Caucau.. i dont think he would be able to run 100m fater than a lot of people, but i'd like to see someone cover him over 25m.. he can just put it on and off, and thats how he beats people..