Best screen protector to use with the Incase Slider?

Have you tried going without a SP? The slider has a tendency (not always, but sometimes) to bubble a screen protector. If you need a SP with your slider, I suggest a very well installed power support crystal or anti-glare film. I prefer without a SP, but those would be your best bet from what I understand if you need an SP.

I have the Invisible Shield by Zagg. I didn't do an excellent job of putting it on but the top and bottom would peel up pretty bad the first few days of owning the shield. After that it is performing better but it is bubbling up a little on the sides. You can't tell from a difference, but it's enough to bother me. Either way, I think I'm going to remove it soon. I'm going to the beach this weekend so I'll wait until after that.

The SGP screen protector is cut a wee bit smaller than the powersupport. It's been tested that you can even install the protector while the iphone is in the slider to ensure no bubbles. Check out the youtube video below.

http://www.youtube.com/watch?v=AlZyacjc8gI

I have my matte charcoal incase slider paired with the PS Anti-Glare. I throw it in my pockets without any worries.

Looks great, no bubbles, no fingerprints

they are 2 for $15 at your local apple store