Static Shock vs Storm - Fantastic Faux Crossover Cover

via Super-Team Family - The Lost Issues

Iron Man Crossovers That Never Were via Super-Team Family

Even more faux crossovers featuring Iron Man created by Super Team Family here.

The Ultimate No-Faced Team-Up - The Question & Rorschach

The epic enigmatic crossover cover that never was 

created by Super Team Family: The Lost Issues

Boba Fett vs Godzilla - "Final Bounty!"

An epic comic cover mash-up from Super Team Family

Han Solo & Captain Kirk - Alt Universe Team-Up Comic Cover

From the awesome Super-Team Family art blog.

All the fantasy team-up covers there are created by cleverly combining and manipulating real comic images.

 This one features modern Phil Noto art - but there are a lot more classic and retro-style covers as well.