It used to be that Dragonite could fly around the world in six hours, but when D/P came out its speed suddenly fell because Garchomp was the newbie dragon. They always do that, because the newbie has to be the strongest. That's just the way it is so it fits that region. Now, Dragonite will always be my favorite, but I do think Salamence outclasses it in bulk. I feel bad for Flygon, as he is is also one of my favorites, but it has many weaknesses.
Garchomp... I'm sorry. But its a shark through and through. The second cousin or something of Sharpedo and was only given the title of dragon because it was supposed to be the next best thing for Sinnoh.
Legendary wise -Rayquaza hands down. Latia and Latios are sweet and are more of the peaceful type pokemon, but in games they are exceptionally strong. I think I am mixing game stats with a bit of personal/pokemon religious belief's and getting them intermixed. Ah well. But with Giratina, its just a freakin' cetipede that should have just been a dark/ghost. Personally, I believe it was given title of dragon because it had wings and they were bored. Though perhaps I am being a bit too hard, especially since I was disappointed in Sinnoh. The increase in 'legendaries' is ridiculous. Should Heatran even be considered one?
Sorry, off topic. But back to topic... yea, go Dragonite...