So the poster on YT, Part-Time Samurai, has been running highlights of some of his favorite Mecha series. So far I think there have been three or four of them, unless I've miss something. They've all been nostalgic fun, and I wish he would continue the theme a bit longer or else cobble up together a new theme of anime videos. It's just it seems like there has got to be more than four or five great mecha series. At any rate, it would interesting to see what else he could do with a post apocalypse themed series, horror series, early anime series, or space opera series. The newest Mecha Monday he covered was Macross or Robotech, which aside from Gigantor was one of the early ones I was introduced to.
Here's is a link to his video on Super Dimensional Fortress Macross!
Here's one to his Moblie Suit Gundam!
And Mazinger Z: https://www.youtube.com/watch?v=cXUBc7SRcFQ