Price: $1.49 per episode
Buy it on: Steam
This is for anyone who is a Half-Life fan -- and let's face it, who isn't? -- who has been waiting for a new game for forever (since it would appear we are not getting one, at least anytime soon).
However, you don't have to wait for a new game to get a hold of exceptional Half-Life content. Although a fairly recent addition to the series, and not by the creators of Half-Life, it has already been praised as capturing the universe and creating a compelling story.