7. Robin - Batman
Probably the most famous sidekick of them all. For all that Batman was superbly realised as a lone-wolf character at points throughout the comic, TV and film series, he was always intended to receive aid from a variety of trusted characters-Robin was his closest ally, and one of the most enduring of the Bat-family. Robin has had, to date, five incarnations, all of them with their own character tics and arcs. The most popular was Dick Grayson, the original Robin and the longest serving. Though he could sometimes appear bland in the comics, and definitely didn't translate well to film he would certainly have been my pick of the bunch. Jason Todd was loathed by the fanbase enough for them to vote in favour of him being murdered by the Joker and his predecessor Tim Drake was immensely popular due to his bravery and searing intellect, which allowed him to deduce the secret identity of Bruce Wayne. While Robin tends to dip in and out of fashion depending on the tone of the current incarnation of Batman, the character is undeniably popular and is well-written enough to survive several re-writes as current Robins take up the mantle of their own separate superheroes, or are bumped off as is the case with the most recent Boy Wonder, Damian Wayne. No matter who is behind the mask, there is a fanbase ready and waiting to explore the character.