SMASH: Pikmin Team

AND THE REST.
You know I remember when I first heard about Mr. Game & Watch appearing in Melee. It came completely out of nowhere but I thought it was a fantastic idea! He is (sort of) the very first Nintendo game character. Some people didn't like him though.
Some people also don't like ROB. Personally I think he's appropriate because rather than representing a specific game franchise he's more of a spokesman for Nintendo hardware itself. kind of like Mr. Game & Watch. Plus, since he's had cameos in so many games (Kirby, Mario, F-Zero, Wario) he's somewhat of a Nintendo mascot in his own right.