Fantastic multiplayer, large and diverse achievement list and with 9 different characters the game keeps giving!

User Rating: 9.5 | Team Fortress 2 PC
This comes with the orange box but its worth the money of the orange box all on its own. There's no single player mode so you're thrown right into the team play. There are 9 very different characters to play as and you can switch at any time as many times as you like. My favourite to date is the Engineer, who can build teleporters, dispensers (to provide ammo and health to fellow team mates) and sentry guns. The Engineer is very much a crucial element in a team's defence. I've found the medic quite fun - it is possible to rack up the points without killing anyone by healing those that are. And the almighty Ubercharge grants invulnerability to both the medic and the person the medic is healing, allowing you both to push your team forward. In fact, all the characters have their specialialities and with a huge achievements list which grants new weapons upon completion, you'll find the best gets better!