I hate it in sci-fi where they have giant beasts with tiny legs - or mega beasts (ie. Godzilla, King Kong, etc.) with human-like physics instead of slow elephant-like movements.

I liked the dwarf-giant in the Thor movie, but really his head should have been proportionally much smaller (like many basketball players) to be closer to "realistic".

A contemporary human-giant in an exoskeleton might make for some decent piece of fiction or sci-fi.