The quote that got me hooked on Yahtzee:
"The only time the game really comes alive for me is when it goes into sheer balls to the wall mindfuckery for a moment. Suddenly, I'm in a dark room and then I'm in another, darker room with a blurry filter over my vision and can hear what must be a moose being strangled in a tin bath. Awesome!" Seriously, that was the line that hooked me on him and its still my favourite xP
There's also the entirety of the Wolfenstein episode, and I can't for the life of me remember which episode it was but I also loved when he said "You *CAN* remove the filling from a Cadbury cream egg and you *CAN* replace it with Branston Pickle, but would that be a good idea? Hmm, gimme a minute." *Pause* "No, no it really isn't."
I also love his post-script in the World Tour review. Can't hear that song now without going
"Put on a trenchcoat and fight some conspiracies..." etc.