Tokimeki Tonight

E.T. the Extra-Terrestrial
A character in episode 21

Frankenstein
Comes to the human world in episode 7 along with the Mummy and the Creature from the Black Lagoon

No

Hulk Hogan
Seen in a newspaper in episode 8

No

Superman
featured twice:

Cameoed in
It's unknown if Tokimeki Tonight has been featured elsewhere.