The Walking Dead: Season 2 | £7.59 | Steam
I just picked this up myself given that my Xbox 360 version appears to have been overrun by game-breaking bugs. Season 2 isn't quite the tour de force that the first season was, but the taut writing and cracking performances go a long way to making you really care once again about the story of young Clementine, and there are some big decisions to be made along the way.
The last episode just emerged, so you can buy happy in the knowledge that there's no more waiting to be had for the complete experience.
You can also pick up season one for under a fiver.