So we've all seen that No$ is great for emulating the DS on a computer, but what have you found for emulating other systems on the DS?

I know there are lists in other places, but I want to see if anyone has personal preferece, tricks, versions we might not know of, etc.

I'll start:
GB/GBC - Lameboy (http://www.ds-xtra.com/Lameboy)
Great compatibility and speed, can use both savestates and in-game saves, emulates RTC (I'm glaring pointedly at my dead Crystal version cart), and among other things will also use your rumble pak (if inserted) for games which had one, such as Pokémon Pinball.

NES - nesDS (I got mine elsewhere, but i appears that Zophar's site is maintaining a version of it: http://www.zophar.net/consoles/nds/nes/nesds.html)
The most convenient NES emulator for the DS I have found; it loads games from your memory card, where the others I have found all require you to inject the ROM beforehand, making one .nds file per nes game. Apparently PocketNES now has a multi-game packer to allow multiple games in a single nds file, but until I try it a bit I'm more comfortable dealing with a file browser, even if it (supposedly) means a worse emulation. Pic related, I've had no trouble at all running this under nesDS.

GBA - Well I've heard good things about that GBA emu for people unfortunate enough to own a DSi, but that requires a specific flashcard, which itself is DSi-only, so the rest of us (myself included) just use some sort of slot-2 device. I personally use the 3in1, and it works great... mostly. I say that because I can't seem to get save patching to ever work right, so I couldn't tell you how to get games like and of the Super Mario Advance or Pokémon or Zelda games running with it. Well actually, the intro-hacked LttP I found seems to have already been save-patched and worked fine, but the raw ROM on the other hand did not. Flashing a game to memory can take a while if it's a large game, and you're usually going to want something else to do for a few minutes. Still, the games work great, so no really major gripes there.

SNES - SnemulDS (http://www.snemul.com/ds/)
This is the most complete Super Nintendo emulator for DS that I have found, and it works well- to a point. The games are usually playable, and the sound and graphics are rendered, but the issue is usually in the fact that the DS is apparently incapable of per-tile transparency and layering, which means that things backgrounds often look messed up in platformers and sidescrollers (No perfect Megaman X emu for me... ;_;) and you'll notice other little visual oddities arising from this. Other that that quirk however, it's a very solid emulator.

That's all I've really tried; I remember attempting to play a Genesis emu once, can't remember what it was called, but it failed pretty hard at the one game I'd hope it would get right- Sonic 2. So that got thrown out pretty fast...

And that's it from me! Anybody else have a preferred emulator on the DS? Share it with us!