I too like the Tiger Stripe pattern but as for what I think is the coolest, I'm not entirely sure but I'm going with the crowd and picking Flecktarn.
I kind of like this Brazilian version of the French lizard pattern so it would be my second choice.
http://camo.henrikc.dk/details.asp?autono=289
For the "What the hell where they thinking?" I would have to pick the Libyan 'Africa Corps' pattern
http://camo.henrikc.dk/details.asp?autono=176
For the one I want to wear if I'm going to take drugs, this one from Indonesia has to be one of the best, besides, nobody will be able to tell if you spill any drinks on it
http://camo.henrikc.dk/details.asp?autono=226
and last, for kind of cool but not quite cool enough
http://camo.henrikc.dk/details.asp?autono=192