Whats your Pick for the "First Doctor Who Episode to Show Friends"?

Been thinking quite a bit on the Topic of what Doctor Who Episode would be the best one to show to People who have never watched the Series.

Previously my personal Pick has always been the 2006 X-Mas Special "The Runaway Bride" for both Showing some good Action, Humour, Doctor Whoisms and even the Darker theme of the 10th Era, all in a Massively Entertaining Package!

But I'm really curious, what would you Pick to show your Friends?