DesMume is a great emu, get the unofficial version at
www.desmume.com which has improved some fps ,it's not much only 4 but when you play the game ,i mean when i play Super Princess Peach i can see the difference.
Also check the compatibility roms at
www.desmume.com , you will enjoy NDS emulation a LOT, just like me
You are wrong guys , Desmume (at least the unofficial version that i use works great and has a faster response then the official version) you CAN PLAY NDS ROMS a lot of them at playable speed.
I am playing Super princess peach right now and it works fine with a few gfx errors at the start of the stage, but still in great great condition, i can't wait other versions of this emu to come out and i hope they increase the speed even more.