If you're looking for the typical clear plastic, here's some recommendations:
Martin Fields - highest quality of any plastic screen protector out there, but you pay for it. A two-pack will set you back nearly $50 after shipping. Imported from Korea I believe. Includes a camera lens protector.
Steinheil SGP - Very high quality and a two-pack will set you back about $13. with shipping. Also offers an anti-fingerprint, but it reduces screen clarity horribly. The full shield (extra $15) is like a Zagg and requires wet application. The clear and anti-fingerprint used a tabbed application making them easier to apply.
Realook - Quality similar to that of SGP. Used to include a camera lens protector but no longer included. Also uses the tabbed application from the SGP (above), plus includes better instructions, is packaged better, and comes with an alcohol pad for cleaning the screen.
Avoid the Seidio. Quality is on par with the Steinheil and Realook, but doesn't have the tabbed application. It's basically peel and pray.
I've used all of the above, including the Seidio. Martin Fields is the clear winner overall, but they are cost prohibitive. Realook is the current champ for me due to cost and the included alcohol pad.