Supreme Commander 2

To add to all the guides above, the easiest map to do this on is Mirror Island, as the cheating AI is right next to the easy AI, and will be decimated in around 3 minutes, if not sooner.

start a match with you and 2 ai on cheating difficulty on team 1 make their bases c and d, create another ai and put him on easy put him on base b right across from you, build up lots of light tanks and rush as soon as possible if your lucky one of your ai teammates will nuke him before 5 minutes goes by if not they will rush with you and finish off his base, another good idea is to send your commander in and set the game type to assassination so all you have to do is kill his main guy and you win easy to do in 5 minutes

As an alternative to doing this against the AI, you can also boost this very quickly with one other person.

Set up a private match on a 2v2 map, I suggest Corvana Chasm. Invite your friend, and make sure you choose two spots that are close to each other on the map (for Corvana Chasm, choose A and C). Don't use any AIs, and choose whatever faction you wish, no Rush timer, and Assassination mode.

Start the game. Select both your Engineers and have them Guard your ACU. Start moving your ACU and have your friend move his ACU so you meet in the middle of your bases. Hit LB and select any helpful ACU upgrades that you can.

Now just attack your friend's ACU. With your Engineers supporting you, you shouldn't even lose any health.

This will also get you the Luddite achievement if you don't have it.