What motorcycle should i buy?

I am 18, i have been riding motocross for 3 years now, cbr 85, yz 125 and occasionaly my dad's yz450. Motorcyles have been my hobby since i was a kid and i am looking to buy one now. I rode my friend's ninja 250 and was very disapointed with the bike, not enough power. I was looking at the triumph street triple i know its a great bike. Any suggestions?