All excellent answers!
DrFrag - Sherlock was great, and you're right, he never tried to hurt any robots, despite hating them.
One character who is more positive, and who I didn't expect to like was Boon. They merged him with Hamegg in the '09 movie and turned him into a villain. Shame, because in the original he was a genius inventor who never got his chance, but ended up saving everyone.
Earthshine - Bem is a great character, too. They have a duty to sacrifice themselves for their planet, but they don't want to do that, and it's understandable why. And their sacrifice in the end is sad, but shows they're willing to save earth from another bomb. Have you watched the Jetter Mars episode that featured them? Their story is very different in that one. Their species travels in egg pods, and Bem survives in the end. I love their redesign, too.
I like the dog lady in that chapter/episode as well. A woman willing to stay behind on earth and take care of the abandoned animals. It's just so sweet and melancholy.
Tetsuwan Penguin - I'll count him, since he does just show up in one episode, in the old series! He's a complicated character, certainly. His love and loss is relatable and who wouldn't want to bring back someone they loved, if given the chance? Only to find it's not the same thing. I did find myself wishing he'd appear again in the 80's series, since his disappearance was never explained, and he could have still been searching for Tobio. He did apologize to him in that version and seemed genuinely concerned about him (and was wondering if he'd fallen overboard, in the Japanese version).
carlymichelle - Pook the elephant was a cute character. It's so sweet whenever Astro takes care of animals. It's a beautiful episode, indeed.
jeffbert - Nice name reference guide! Your fave doesn't have to be from the 80's show; it can be from the 60's show, if you want. I liked the kid Buyou (sp?) from episode 101: Dangerous Mission!