The ending of the Zero Punctuation review of Tom Clancy's H.A.W.X features Yahtzee and one of the imps holding up signs featuring It Was His Sled moments. This Troper was confused for a while about why he did that, and then found the point in the middle of the video where he says "I'm going to give away some spoilers, so if you're that bothered, stick your head in a bucket 'till the generic metal starts up." It still took a few moments to get the connection. - Shotgun Ninja
In the review of Split/Second:Velocity Croshaw stated (via a metaphor) that he is good at oral sex, but doesn't like it. Seems like a typical "I'm awesome" joke, but later I stumbled upon his blog. He's asexual.
In the captions over the end credits to his Silent Hill 2 review, one of the jokes is "There was a critic here. He's gone now." At first it looks like a joking reference to the famous Memetic Mutation line "There was a hole here. It's gone now." from the game itself. But it actually makes a lot of sense in context. Ordinarily, Yahtzee's a critic in the harshest sense of the word, who runs on Accentuate the Negative and puts down games as nastily as possible. For this video, however, the "critic" part of him is gone because he just wants to gush about a game he loves and ignore its faults.