A lot of gaming characters have sidekicks. Mario has Luigi and Yoshi. Sonic has Tails and Knuckles. Alis has Myau. Link has Navi. Out of all the sidekicks you've seen in games, who were the best and worst ones?
Personally I always liked Rush in Mega Man. I'm usually not a fan of dog characters, but I found Rush really useful. The variety of transformations helped to keep things fresh and interesting.
The worst, IMO, is Baby Mario from Yoshi's Island. He's helpless and useless. A complete waste of pixels if there ever was one.