List of the best generation 4 Pokemon, ranked by fan appeal. In the first three generations of Pokemon there were 386 Monsters, with the fourth generation introducing another 107 Pokemon in Diamond, Pearl, HeartGold, SoulSilver, and Platinum. Generation 4 introduced some unforgettable Pokemon like Lucario, who would eventually go on to be a playable character in Super Smash Brothers Brawl.
There are other lists that rank the greatest gen 4 Pokemon, but this is the only one that you can actually vote on and make your voice heard.
http://www.ranker.com/list/best-generation-4-pokemon/ranker-pokemon,
Lucario
Palkia
Darkrai
Dialga
Giratina
Arceus
Empoleon
Garchomp
Gallade
Infernape