Super Mario Bros. Crossover 2.0 is out! An expansion on the original game, which let you play as various NES characters transplanted into Super Mario Bros., but using the rules and abilities of those characters from their original games, version 2 offers more special abilities, more characters, and your choice of audiovisual "skins" based on four Mario games from the NES, SNES, and Gameboy, along with one based on Demon Returns. There's even instructions for playing with a gamepad! For more information, see the Super Mario Bros. Crossover Wiki or watch the exciting Super Mario Bros. Crossover trailer! [Previously]
Abobo's Big Adventure : apparently the Nintendo Entertainment System DOES blend.
Metroid Cubed...Squared! It was linked a couple years ago, but since then the site has undergone a major overhaul and added a bunch of cool stuff. [Flash Warning] In addition to the now classic voxel 2.5D conversion of Metroid (playable and interesting), there is now a robust Metroid world-editor, a Marble Madness-like prototype using the voxel engine, a StarFox level editor and model viewer (Spoiler: gfx not as good as you remember), and numerous others worth checking out: Hyrule Planetoids (comme Le Petit Prince) and a OpenGL Zelda room viewer, a Mario 64 Explorer, and numerous Super Mario Bros demos. It's all quite useless/amazing.
Super Mario Brothers sound effects. Boing! Boing! CRUNCH! Ding! Ding! Ding! Whoop! Boing!
Michael Jackson is guilty of being totally excellent in this fantastic whirlwind tour of NES games (a la Sega Fantasy VI); MJ herein imposes his 16-bit self on a huge amount of games including but not limited to Megaman, Kung Fu, Ice Climber, Super Mario Brothers 1 and 3, Dragon Warrior, Arkanoid, Track and Field, Spelunker, Final Fantasy and more. If you know the Japanese language + games, clue us in. (Flash and hardcore midi dance music warning)