I got a screen protector in an inexpensive eBay pack of
case + 2 chargers + protector (thanks, TVCCS, for originally providing the link to that). Using the video in the link above provided by guyd, I was able to put this protector on perfectly. Given my older, dryer, hands, I'd say I have less capacitance than most people. Even so, the results have been perfection! I don't experience any difference in feel from the bare screen. There was even a cutout for the proximity sensor.
I've tried regular screen protectors on touch screens before, but among about 30 applications, I always got bubbles. I figured that was inevitable. But not this time, thanks to the video instructions. Use the video linked above, putting it on sideways, instead of top to bottom in portrait. Also, this inexpensive screen protector has front and back pull-off disposable plastic, with tabs, like in the video, which helps immensely to keep you from touching the screen protector at any time during installation. This eBay seller sells them alone without the hard case or chargers. The Clarivue protector linked above is probably just as good, and maybe all modern ones are too.
I've applied Zaggs and similar (from Case-Mate), and can apply that type of wet-applied screen protector perfectly. But it added friction to the one capacitive touchscreen that I've applied it to, a Zune HD. That friction seems to be the cause of impaired responsiveness on the Zune. I bought a two-pack of these wet-applied full body protectors for the Optimus, but I'm glad I didn't try them.