Rincewind the Wizzard was the primary character in a span of computer games based off the novel series. Considering Tony Montana, a character from a movie that wound up made into a game, made the list, it'd be a damn shame if Rincewind didn't.
Thankfully he did, and when the next list comes around, while Montana might not make it, he will. He really is a good character. The only reason I'd keep him really is because Rincewind could be recognized more as a game character then Montana, who is definitely more of a movie icon.
Also, "great skill in magic" was indeed sarcasm, Skummy, so don't worry
As a huge fan of the Discworld books, I'd really have to challenge that point. He's been in at least half a dozen novels as the main character as well as a few cameo appearances all over a massive series spanning something like twenty or thirty years, while he's appeared in two video games.