As a sister post to the one about map resources, this one is about supers-themed minis (which again, amounts to just about everything but fantasy themes, because fantasy minis are everywhere).

Pre-made minis:  Superhero Miniature Resources – (Re)Turning (to) the Tables (drl2.com)

3d printables:  3d Printed Superhero Minis – (Re)Turning (to) the Tables (drl2.com)

Please let me know if there are others I've missed!