I don't use screen protectors and Meteos was fine on mine, I think it's because even when things get crazy you have to stop and think which pieces to move, which stops you from frantically carving into the screen. Or something.I remember everyone saying Meteos has ruined their screens from playing too much. I actually didn't play too much of it so I wouldn't know.
I vote none... Only game posted in this topic that I didn't fully beat yet was Canvas Curse and my touch screen is spotless! And no, I don't use a crappy screen protector, I'm just careful with my stuff.
I really noticed it when I saw my friend play his DS. He is tapping hard, making fast uncareful moves and such. While I instead, I never tap the screen. I always *touch* it. And always do careful slides.
Mario & Sonic olympic games > all mentioned games put together.
Especially 400m hurdles was a painful experience for my ds phat