Good to hear that you had a good experience with the HORI brand. Personally, I left my 3DS naked. And regretted it, since the top screen now has 2 pretty deep scratches on it.

My psp started off scratched up, so I didn't bother with a screen protector.
That's cool that your phone and ipad never ended up with scratches though. The screen is made out of a really tough glass, so it shouldn't scratch, yet I've had horrible luck with that. I used to have a sony xperia, the first one they came out with, and, somehow, it ended up having a dent in the front--a small dent, but it was much wider than a scratch. I'm kinda ocd when it comes to my phone screens, so it drove me nuts for the time I had the phone. So after that, I've HAD to get screen protectors. Lest they end up with dents. Ugh. Then I have to make sure the screen protectors don't have dents or hair underneath... but that's a whole 'nother story.