League of Legends is the reigning MOBA king, with more colourful champions than you could hope to become an expert with in a single lifetime. And it’s free, as well. Thanks to Riot Games and one of the best gaming communities around. You can even find your own champion skin.
League of Legends Minimum Requirements
2 GHz processor
1 GB RAM (Windows Vista and 7 users will want 2 GB of RAM or more)