Muteki Koujin Daitarn 3

Both feature a MoTW formula, robots, great jokes, a story that develops on the background and several references to western media of the time. Their last scenes were strikingly similar as well, although you'll have to watch them to see for yourself.  

Episodic shenanigans of a cool guy with a dark past and two female characthers. Mostly comedic but get dark towards the end 

Suave renaissance men who have mysterious pasts pilot larger than average mecha with help from classy butlers and capable female companions. The mechs are the selling point of the shows, but both main characters are skilled inside and outside of their robots. The plots are mostly episodic. The Big O is more serious, but has a sly sense of humor. Whereas Daitarn 3 is very comedic with occasionally dark undertones. Lots of fun. 

These two shows are among the best of the old school of super robot shows. They both have interesting characters and fairly interesting ongoing plotlines behind their episodic natures. 

Zanbot's companion series; A bit lighter in tone but it still has a grim ending. Again, directed by Yoshiyuki Tomino. 

Directed by Tomino, except this is more of a Western with mecha than it is James Bond with mecha. Xabungle is extremely goofy and perfect for making you laugh, just like Daitarn is. 

Wacky, nonsensical, Tomino-directed giant robot shows with great action scenes. Daitarn 3 is old and a bit ugly, but like any good Plain Jane, it more than makes up for being unattractive by having great character(s) and charm.