Metagross. You all say Speed isn't everything. That's true, though it does matter with some Pokémon. But you forget that Metagross gets Agility =O Get Metagross 198 Speed, and one Agility will take its Speed high enough to outspeed anything besides Ninjask, Electrode, and Deoxys E. So, with one Agility, you now have a Pokémon that is incredibly fast, incredibly strong, amazingly durable, and endlessly versatile. Couple in the two weaknesses and numerous resistances, I have to say, what more could you ask for?
Salamence is also excellent, and after two, even one, Dragon Dance, it becomes terribly hard to get rid of. CBMence is also something you wouldn't want to face. 600+ Attack and 300+ Speed destroys just about everything. And then there's Elemence, a rarer form of Salamence that makes use of its incredible Sp. Attack(Base 110) and surprises a lot of common switch-ins for Salamence.
Tyranitar is great as well. If you look past the various weaknesses, you'll see a well-balanced Pokémon, who, like Metagross, has the ability to raise its low Speed(Dragon Dance). STAB'd Rock Slide after a DD off an enormous Base Attack is nothing to laugh at, and Tyranitar has a bunch of other deadly moves to deal with the Pokémon that resist Rock Slide.
Dragonite.....Meh. It has just as much Attack as the other three, but it's a bit slow to make use of it. Yes, it gets Dragon Dance. But its weaknesses counteract that boost, seeing as anything with an Ice attack is just going to laugh at it.
That sounds rather hypocritical, seeing as Tyranitar had twice as many weaknesses as Dragonite. But Tyranitar has excellent HP and Defenses, meaning unboosted SEs aren't going to KO it. It's fairly easy to switch Tyranitar in, too, seeing as it has a fair few resistances. Dragonite resists Grass, Water, Fire, and the like, but a Pokémon that carries moves like that typically has something else that would damage Dragonite badly(Sceptile, a Grass user, has HP Ice. Suicune, a Water user, has Ice Beam. Salamence, a Fire user, has Rock Slide).
The only common Fighting attack used in today's metagame is Focus Punch, and it's fairly difficult to pull off against a Tyranitar, because it was made to get in the game and kill. There aren't any Ice attacks like Focus Punch, and Ice Beam is everywhere in today's metagame; Dragonite can barely switch in on Blissey for fear of being IB'd(even Blissey, with its mediocre Sp. Attack, still takes ≈75% off Dragonite). Dragonite is just too slow to counter its weaknesses.
And, what's more, its Ability is terrible. Salamence can switch in on common Physical attacks due to Intimidate; adding in the fact that most Salamences carry HP Flying, the threat of that and Intimidate stops Heracross cold.....But, what's Dragonite going to do to Heracross? OK, so it switches in on the Focus Punch or the Megahorn, both of which it resists. And it carries HP Flying(possibly). But Heracross is faster than DDNite(264 Speed is what you aim for with DDNite, which outspeeds everything Agiligross will after one DD), and without Intimidate, Rock Slide is going to annihilate Dragonite(unless it's a CBCross, which aren't as common).
In short, why use Dragonite when you have Salamence? Woohoo, Dragonite gets Ice Beam and Focus Punch! But why would you use Ice Beam on a Physical Pokémon like Dragonite? And why bother with Focus Punch when the whole point of DD is going before your opponent? Salamence gets Rock Slide, and that more than compensates for the lack of FP and IB, seeing as it benefits from DD and covers a lot of Types. Dragonite is still usable, it's just a lot harder to play than Salamence.
≈*V. Tsun*≈
The 8th Champion