I watched Shinkalion purely out of desperation and was pleasantly surprised despite being a show for kids and having "terrible graphics".

And yeah there's not much mainstream, but you always get some Mazinger spinoff, some Gundam and other "minor" stuff. The genre is definitely not popular but it's alive.

Super Robot Taisen is also still ongoing, and while it's not a show (although it's been adapted a few times) it's a good way to find stuff that might have escaped your radar. And the originals can help quench the thirst for new cool robots with flashy moves. Lately they have been adding "never animated" stuff like Mazinger ZERO, GaoGaiGar Vs. Betterman and Getter Devolution which is nice too.