I can't say much for any of the other screen protectors out there. But the Zagg Invisible shield has worked really well for me. I haven't had any problems with it and it's kind of hard to argue it's actual protectiveness. I mean just look at some of the demos they do. (Youtube it)
The only 3 downsides to the Zagg shield for this phone that i can think of are:
1. They don't have the anti-glare or smudge proof shields out for it yet.(<-- Are very nice)
2. They are a bit pricey. But they do have a lifetime warranty that from what i herd is actually handled pretty well.
3. The biggest thing is that they are not the easiest things to put on correctly. I work for The Geek Squad so I've had plenty of practice and can do they them in my sleep. But for someone that has no experience with them, i would suggest just paying the money to have geek squad do it. (It's only a few bucks on top of the price of the screen and the work is guaranteed.)
A lot of the horror stories you've probably herd about the Zagg shield comes down to the person not giving the screen enough time for the adhesive process before hardcore use.
I always tell clients that very little use for the first 24 to 48 hours will reward them with the best results. People, you have to understand that with the water based screens until the adhesive process is fully complete. To much pressure on the screen can and probably will cause it to drag, leaving horrible marks and bubbles.
I am in no way representing Zagg or saying that there products are better than others. Especially because i haven't used any others.
All i am doing is laying down the facts and letting you guys know that i haven't had any trouble or issues with my Zagg shield on this phone.