I defy anyone to talk about PC gaming seriously without talking about Valve Corporation. They are massively important and have done nothing short of revolutionise this medium that we love. It’s easy to forget everything that they have put out there; classic game after classic game, and then a system that has even completely changed how many of us buy and play games. Here we have every game they have commercially released, affectionately recalled by both us here at Gaming Daily and the people who these games mean more to than anything else out there – journalists, gamers, clan members,…