Pac-Land ruled too and it's even older than Super Mario Bros. And it's technically more difficult too since it has 2 way scrolling (parallax scrolling).
especially the joystick routines are interesting in that one. It took a while before I figured out how to jump over that pond
I was a Wonder Boy addict but that came out after Pac-Land and SMB.
A.: right, lawyers are happy that those exists so they keep an eye on it and warn the owners if they bump onto an issue.