So this awesome person by the name of megacocorock has made Gameboy-esque covers of a lot of anime music. Here's what they're capable of:
Some others I like are:
Mezase Pokemon Master (Full)
Kimi no Soba de
Anything else can be found at their channel. As long as it has a Pokemon picture and the name begins with FC then it's 8-bit.
Apparently they've made every intro with the exceptions of Rival!, Mezase Pokemon Master (Whiteberry), Symphonic Medley, and Spurt. And they also covered some more endings and versions.
And if anyone says these suck, then I dare you to find a better chiptune version.
Aside from Pinball's Mezase XD