WORLD OF WARCRAFT
This was a tough decision. My top two are both great games. I love world of warcraft. First I should begin with my personal background within the world of warcraft. I started playing at 2 to 3 years ago, primarily either a paladin or a mage. At first I was really into the pvp aspect of the game. I decided to reroll a warrior afterwards, dedicating him mainly to PvE. The warrior was one of the best tanks on the server at the time, and managed to clear endgame content not too long after release. There were times I would spend up to 20 hours straight in one sitting just gathering gold. I to this day still play, on and off. World of Warcraft will forever remain in my heart.
(all images are from imgur.com)