A Taiwanese player has has become the first to complete every single one of World of Warcraft's achievements - which is probably as close as anyone can come to "completing" the game.
MMO Champion (via GamePro) reports that the character Little Grey, a Tauren Druid, is the first and only player to have 986 out of 986 achievements listed on his Armory page. (In fact, he's missing one World Event achievement, but a bug has balanced it out with 165/164 PVP achievements.)
Little Grey has 100 mounts and 75 vanity pets; has completed every quest in the game, visited every location, and defeated every dungeon and raid boss; has made over 100,000 valid player kills in PVP and achieved 100 victories in each of the game's Battlegrounds; has achieved Exalted reputation with 40 separate factions, and more.
According to Little Grey's Armory stats, the character has played 2124 Arena battles, taken 1911 flight paths, completed 5906 quests (an average of just under 15 a day) died 8543 times and killed 496,539 players and creatures. Little Grey has also hugged eleven times, waved once, LOL'd once and has never cheered.