I'm a huge fan of the Half-Life series. In fact, I'd probably say it's one of my favourite games of all time. Ever.
So when I stumbled on this youtube series of a dude playing the original half life, with running commentary of the contents of Freeman's mind, it was an instant hit with me.
I'll link you to the first video… he has made 25 episodes so far, which sadly isn't the whole game, but I hope there are more on the way.