Kaiketsu Jouki Tanteidan

Both shows feature: A detective style character (Narutaki and Roger Smith) A female aide (Hsu Ling Ling and R. Dorothy Wayneright) A butler (Kawakubo and Norman Burg) A big tough robot (Goriki and the Big O) An ally on the force (Onigawara and Dan Dastun) Outlandish villains A dangerous city as a setting  

They both star a kid detective, except that this series takes place in a London-esque town that is also powered by steam. Both shows were animated in the mid-to-late 90's, so if you like traditional cel painted animation (that still manages to hold up) I highly recommend it! It could also be a great gateway anime for comic book fans, as the villains in this series wear costumes to conceal their true identities. 

Both feature a giant robot remotely controlled by a kid detective and have a similar setting. 

both are set in the 1920's. They feel similar with the robots and steam and other stuff. 

Both animes have young protagonists who're cunning, yet innocent in a way. They have Hot looking sidekicks and of course, backed up by their budding and loyal Robots. 

Both shows include Robos on some important job to help people! (rescue robos in MRR and police robo Goriki in SD). these robos are controlled by kids. + there are bad robos who create crimes and disasters