Actually, the worst Dragon that even has ANY competitive viability is Gabite. Gabite should be NU. Not NFE. And Salamence would be the best because it looks cool and it is ultra-powerful. And if I wasn't an idiot an chose only one, my 2nd choice would've been Dragonair. It looks cute. Dragonite looks ugly. Come on, Dragon+Duck=EPIC FAIL and it's ugly.
EDIT: Yes, I know that Altaria sucks.
Dragonair: Looks really cool. Dragonite: Whether its power or look or the early anime appearance, Dragonite definitely got it all. Kingdra: Who wouldn't like this ultra-ferocious, Swift Swim sweeper anyways? Salamence: Tough and strong.