He is one the most unappreciated character in the Mushroom Kingdom. But in the real world, his popularity is OVER 9000!!! He won a character comparison against Daisy, he's the opposite of Luigi, and most of all, he's got an army of Bob-ombs!!!
He's Mario's younger brother and he's easily scared. Just the look on his face when he got slammed with King Dedede's Hammer in Super Smash Bros. Brawl! ROFLMAO!!! In Super Paper Mario, he was a boss as Mr. L. We can pretty much know the outcome of the battle.
Now, there are some reasons he would come in first. He is Waluigi's brother, he has an army of Bob-ombs, he has his own game series, and he's down right funny! Why did he come in third? HE'S FAT!!!!!!!!!!!
Everyone's favorite plumber! He's the head of Nintendo, Peach's hero, and has the most awesome video game EVER!!! Why in number 4? BECAUSE I SAYS SO!!!!!!!!!!!!