I’m a fan of his game reviews, so I was delighted to see he had made games of his own, which can be seen here. I personally think he’s pretty awesome, but I can;t be the guy who’s first making the SDMB aware of him, can I?
I’ve been reading his reviews for a couple of months now and have been enjoying them.
I haven’t tried any of his games out, although there is an amusing youtube video somewhere of someone trying to copy Yahtzee’s style while reviewing Yahtzee’s own game.
He’s come up in several threads before, and the SDMB is how I found out about him. He’s part of my regular Wednesday internet time-wasting rotation. 
I’d been thinking about starting a thread on the Chzo series. It’s four games, each of which can be completed in a couple hours, in the style of the old Sierra adventure games (King’s/Space/Police Quest). For what they cost (i.e., nothing), they’re about as good as you can do.
The full series is 5 Days a Stranger, 7 Days a Skeptic, Trilby’s Notes and 6 Days a Sacrifice.