If you're more into having fun than working on your EPIC KD RATIO BRO AW MAN AW MAN then you'll like tf2. This game has nine balanced classes to chose from- you can be a powerful tanklike Heavy, a stealthy backstabbing Spy, or a quick, agile Scout. This game, being a class-based shooter, has all sorts of weapons as well as fun hats to equip to your classes. Also having lots of maps, both from valve, and from creative community members is a plus. Best. Game. Ever.
