Gears of War 2

This will take less than 5 minutes, simply set up a private xbox live match on execution 1 round and using a friend, second controller or bots simply sign in another profile, and using all 3 maps which are Fuel Station, Gold Rush and Flood simply kill the second person on all 3 maps and the achievement is yours.

For this achievement you need to win a match on each of the 3 new maps from the Combustible Map Pack DLC.

Here's a list of the 3 maps you need to win a game on for the achievement, use it to keep track of which maps you win on;
• Flood
• Fuel Station
• Gold Rush

Now the achievement is left entirely open as this can be obtained by winning a match in any mode (except wingman), so while you have the option of playing online in a ranked/social match and working toward this achievement casually you can also choose to get this achievement out the way by playing a local game with 2 controllers.

The quickest way to get this achievement is to set up a local game, set the game type to Warzone, set the round limit to 1 and work your way through the maps while killing the second player, this way you have absolutely no threat to contend with as the second player won't do anything unless you make him.

You can use this method any way that you want, you can set up a match with you facing off against a team of bots if you want, it's entirely up to you, I've just outlined the easiest and fastest method that I know of.