id242 I wasn't trying to be sarcastic. I was serious!
AFAIK there are no better emulators than the two you mentioned, except the leaked Ensata emulator that works with very few ROMs (But those it does work with; work quite well! (Don't ask where to get that emulator by the way, it's an official Nintendo emulator that has been leaked quite a while ago now if you didn't know that already)).
Besides emulators, the only other option is to use the Nitro DS system that developers and selected game reviewers have. You may have seen it, it's a large blue box with a hefty lead connected to a DS through the DS card slot.
The game cart is inserted into the Nitro box and can capture video/image output from the two DS screens.
IGN use this for example.
And last but not least, just get official screenshots from the game developers.
Other than that; you're out of luck mate.