4. Fallout 3
Really any number of Bethesda Softworks' numerous sandbox style adventures could have made this list, and with the massive & continuing success of 2011's Skyrim, it was a tough call on which to include here. However, I finally narrowed the decision down to their post apocalyptic masterpiece, Fallout 3. Set in an alternative version of the United States some 200 years after a nuclear apocalypse, the player takes on the role of a lone wanderer, whom traverses the baron landscape searching for aid, companionship, fortune or virtually anything the player desires. Its vast interactive landscape, many hidden treasures and dense and layered storytelling have kept many players captivated for weeks on end, searching every nook and cranny of the game's massive map for every little Easter egg or hidden weapon to be found. The game's impressive downloadable content continued the main storyline long after its initial plot was over, and added in even more expansive areas to explore and fun to be had.