My favorite twist is the fact that the female Jordan Hester turns out to be the baddie and tries to kill Harold. It is not a major twist, and it is not completely unexpected. After all, our boys have an awful tendency to just ASSUME that the female Numbers are not a threat, and then they turn around and get burned by them (See: Caroline Turing aka ROOT!!). But the female Jordan Hester is my favorite twist because it gives us the chance to see Harold Finch stoned. And that makes me smile!
(gif courtesy of Gauna- 03 -
http://gauna-03.tumblr.com/)