I'm buying my games legally, so the only ROMs I now have are Sonic Rush E3 Prototype, Sonic the Hedgehog 2 Nick Arcade Prototype, Mario Kart DS Beta and several MKDS and SM64DS Hacks.
And as for Emulators, I don't use Emulators for playing, but testing ROMs, which could brick either my DS, or one of my flashcards.
-Game Boy/Game Boy Color
-Game Boy Advance
-Sega Game Gear/Master System
-Sega Genesis/Sega CD/32X
-Sega Saturn (I can't get this one to work, however. I'm itching to play the Saturn versions of Sonic 3D Blast and Mega Man 8.)