Which verification sites are the best or most widely accepted? I know TER has a whitelist. Others have referred me to P411, RS-AVS, and some have their own methods. I don’t want to send my info to a bunch of different places, I would prefer to do it only once to protect my privacy as best I can. Thoughts?

Because anyone can click on it without actually knowing anything about you. While P411 is far from perfect it's really the only site that has any credibility for verification, although many girls will also require additional info.