Tough choice, in all honesty.
Bagon VS Dratini = Bagon
Shelgon VS Dragonair = TIE
Salamence VS Dragonite = I'd have to go with Dragonite on this one.
I do think that both their designs are great, and the moveset is decently good. Also, I'm quite nostalgic and I love Kanto, but Kanto is tied with Hoenn. In competitive battling, Salamence would be better. But, I still voted for Dragonite.