I watched Laugh-A Lympics on ABC Saturday mornings, but it never was a favorite of mine, though. Yogi's Ark was more memorable to me.
Hands down, Super Friends was my favorite Saturday morning cartoon of all-time, though it really became good with the introduction of the Challenge of the Super Friends circa 1977.
Mighty Mouse? I became a fan once his program went into syndication during the Seventies (seen on WPIX in the NYC area). Same goes for the other famous Terrytoon creation - Heckle and Jeckle. I also remember Deputy Dawg and Hector Heatcote shorts, but I don't recall if they appeared on MM or H & J.