The Stanley Parable is one of those games that you just can't miss. It's one of my favorite indie games ever.
I was intrigued back when it was the original edition, and I watched that entire playthrough, which was only 30 minutes or so. When I found out it was updated, and it was over 3 hours with all the endings, I knew that I needed to check it out.
I remember playing the Stanley Parable back when it was a mod for Half Life 2. It would have been worth the price back then, the updated edition just makes everything better.