I have a cover case from Buy.com and ruined the screen protector because I wanted to get ALL the bubbles out.
I then immediately decided to go to Best Buy and of course the only case I saw and the guy sent me to was the ZAGG shield. I decided to let them put it on even though it costs $14 to do that. They did an amazing job except for a few micro bubbles which I was told go away after 24-48 hours. I like the shield. As long as it protects it and doesn't mess up, I'm happy.