Bring back Titanosaurus...
Titanosaurus is a strange beast. It's one of the most popular monsters in the US, but if I'm not mistaken, one of the least favorite in Japan. As much as I would like to see my favorite amphibious dinosaur again, it might be best that he does continue to enjoy his retirement. Otherwise, I'm afraid he might get the Zilla treatment from Final Wars.
You gotta admit though, he and Mechagodzilla made a Hell of a team.