Emulation *sigh* nothing like playing all the old favourites once more.
For NES I use NESter
For SNES I use SNES9xw
For SEGA MegaDrive/Genesis I use WGensEmu
I've got quite a collection of games, I sometimes place my favourites on my site (No, I'm not advertising, you wanna check them out view my profile). I've been hooked to Dragonball Z Hyper Dimension for SNES lately, I love playing as Goku and hitting Cell or Kid Buu with a fat Kamehameha!