I don't like screen protectors. I bought a Nintendo box with some accessories, one of them were screen protectors. When I tried to put them on, the DS looked fugly, I had to push the touch screen harder (which made me nervous) and there was a weird sound coming out of it each time I clicked.
When I removed it, a bit of glue sticked there (only on one corner though, phew) and I had to find a way to get it off. I just went using my DS around and it's all fine.
The touch screen isn't that fragile. Sure, it gets all scratched over time, but that's normal, you don't really have to worry.
My friend's dad uses the same Palmtop for over 15 years. You can imagine how the screen looks. :x
Case protectors are a must, though. Don't get one of those that you can put games and blah, try to get one just for the DS. It's safer.
I have a game case and a DS case. The DS case is all comfy and blah, and the games case is resistant if it falls.
Lemme search for pichurz.
That's the game case. It's pretty good, and comes with an extra stylus. Nintendo official if I'm not wrong, but it's not expensive at all. Up to 6 games.
Still trying to find the case pic. :U