Iron Man and Space Ghost

Lately when Chemo is featured in the comics, he has some kind of robotic appendages attached to him.  He still looks cool, but I still favor the more simple classic design, as used on this cover.  A giant sentient container of bubbling toxic waste is a terrifying concept and his appearances always excited me as a kid.

Dr. Fate and Brother Voodoo

Brother Voodoo was a third-tier character and even considered kind of a joke for a long time.  I was never sure why, I always thought he had a cool look and I liked the connection to his departed sibling.  Fortunately he has gotten much more of a push in the lat decade or so, and It's cool to see him finally getting the respect he deserves in the Marvel Universe.