Showcase: Games That Could Have Been, by Marinko Milosevski

I would play the hell out of all of these.

[Games That Could Have Been
by Marinko Milosevski]

Showcase: Blake Wheeler's NES Cartidges

"Cartridge No. 1"

"Cartridge No. 2"

"Cartridge No. 3"

[Blake Wheeler on Deviantart]

Showcase: Adventure Time Famicom Cartridges

These are pretty clever. Check out the link below to see some shots of these cartridges in action.

[SimplyAWFUL's Adventure Time Collection]