For being based on a gimmick, I agree. The thing is you can only have one of these. Anything even vaguely similar will just a a knockoff. For a less memorable gimmick song, anyone remember Cotton Eye Joe by Rednex?

What impresses me is Billy Joel's range as a musician and song writer. Piano Man, Movin' Out, We Didn't Start the Fire, and Longest Time are all popular, but so different.