With very few exceptions, I don't like using my PSP for emulators. There are better systems for that. I keep an Atari 800 emulator on there for a few games that I love, a SNES emulator because I haven't convinced myself to get rid of it... and that's it. If I need to emulate the Genesis or Sega CD, I do it on my computer, or better yet, play on the actual hardware. Same with SNES. I never used my MSX emulator, and the Game Gear one sucked. The Atari one is just too convenient; I don't keep the Atari set up in my room, and it's pain to pull out and reassemble. Not to mention a lot less wear and tear on those floppy disks.
"I'M THE MAN WHO'S GOING TO BURN YOUR HOUSE DOWN!
WITH THE LEMONS!"