Absolutely, Jar Jar. Anybody putting in other names is just trying to be cooler than the next guy with their non-conformist originality.
The only alternate answer I would accept is Mr. Lucas himself for creating him and slowly turning my most favorite movie of all time into an ever worsening spiral of childish humor wrapped around the least cohesive story lines I have ever seen in a series. But unfortunately, he is not fictional, so Jar Jar it is.
The Wonder Twins are a close second for ruining my childhood cartoon heroes. Even when I was young, I knew they were just wrong.
With great power comes Awesome irresponsibility.