Well, as European, I can confirm that UK socket design is the best, at least in this part of the world. But, it is not because security features. It is because it is very, very easy to plug in! I really hate EU sockets as they are hard to plug in, especially when plug has only 2 connectors.
I swear every time when I have to charge my cell phone...
Disclaimer: I live in Serbia (EU sockets)
It is easier to write an incorrect program than understand a correct one.