The fact that I have a Dreamcast with a VGA box that makes it look super sweet doesn't quench my curiosity. Plus, on the PC, I can play with USB arcade sticks, and that makes fighting games much cooler. Plus, emulation is about the curiosity - even when you don't have the original hardware nearby, you can see how it worked and what games it had. To me, it feels mysterious and that's what attracts me. Well, that, and it's convenient to have my NES and SNES games on the Wii.
Why do people use emulators at all? It's not like there's a world shortage of any of the popular emulated platforms. Most people just like the convenience (yourself included by the sound of it) and the price (can't beat free), or prefer upscaled graphics. I think the argument for emulation of platforms with 3D acceleration (N64, DC, PS2 etc) is actually much stronger than for older 2D platforms. In most cases I still think it looks ugly, but they do scale to a higher resolution more gracefully than the horrible interpolation filtering that most 2D-era emulators feature. The only interest I have with emulators is the technical aspect of seeing what's possible. I haven't played a game on a PC emulator (as in properly played) for God knows how many years.
The last piece of emulation i did was with with a Gamecube emulator just because i was curious to see how well it would run on my PC and i did get markio kart DD and Mario sunshine to run and be playable but others i tried where too slow. To be honest though i don't like to do emulation, i'd much rather buy the real physical system and games than having a bunch of files on my PC.
I use emulation simply because I dont have the space or time to play video games that much now. Thanks to emulation I don't have to be either having my room with everything set up and less space (its small as it is) or have to be always getting it out of a cupboard. Its also helpful for games that don't have saving features. I don't have the time to play through an entire game in one sitting
