Lance oozes coolness. Silver is a great character as well. The battle with Red in G/S is my favorite moment from ANY video game. Period. Although he is more recent, Cyrus from Platinum is by far my favorite NPC. He genuinely scares me, and that moment after you battle Giratina, he just walks into the abyss of the Torn World! Where time doesn't flow and space is unstable! Very creepy. Oh, and that Team Rocket duo that you fight off with Lance. They bear a striking resemblance to "Team Rocket" in Yellow Version, who are of course based off of Jessie and James from the Anime.
Although I don't remember his name, that dude in the Emerald Battle Frontier that says, "I SWALLOW SLUDGE TO TRANSFORM MYSELF". What on earth?
There can only be one Cat Mario.