8. World Champion - Ghost Recon: Advanced Warfighter
Here's one that's really not worth the effort, and you'd have to be absolutely insane to even bother trying. The achievement requires the player to be ranked #1 in the world on the online leaderboard, which given that the game has been out for 7 years, is a ludicrous demand. You don't have to keep for the spot for more than a second, so there's that, but the sheer number of man-hours it would take even the most skilled player is staggering. Most players would likely resort to just boosting with a friend to reach the top spot, but given that the leaderboard numbers in the millions of people, do you really want to waste a chunk of your life climbing the leaderboard on a game that nobody really plays anymore? Oh, and you only get 40G out of it. How stingy...