I would stay away from proXPN. I looked into them when they started sponsoring Security Now, here is what I found.  https://twitter.com/proXPN/status/326869677122936833

Their whole attitude toward it was a huge turn off for me.  

AirVPN is based in France, PIA looks like a great company, but after Lavabit I am not sure we can trust any US company anymore.  Being based in the US now seems to be a liability rather than an asset.