In Infocom's text-adventure Planetfall, Floyd is the damnedest little annoying robot: He runs, he hums, and he asks you to play Chase-and-Tag. Chuck Wendig pens his paean to Floyd because he makes you feel.
Co-operative play isn't usually about hero and sidekick playing together, but Ryan Smith shows how the sidekick feature in Super Mario Galaxy 2 is perfect for him and his casual gamer girlfriend.
When playing a party-based RPG, your companions are equivalent to sidekicks, moving along the story and providing color. Peter Parrish tells us of one of the most unique characters in recent memory, the planet Democratus.
Nobody likes to be told what to do, especially while playing a videogame. But Brendan Main argues that is precisely why Navi from Ocarina of Time is the best sidekick ever.