Star Wars: The Force Unleashed II

Right after learning Mind Trick (hold LT and press Y) not even halfway into the First Level "Escape from Kamino, you will be told to use it on a lone Storm Trooper patrolling a balcony. He will jump off the structure and following him you will navigate your way through an area filled with Red Force fields and shield generators. Although the achievement says to have your mind controlled enemies jump to their deaths, having them jump into these fields to disentegrate or into an object that will harm them also seems to count; it is however important to note that getting enemies to do this is hard when the force power is level one and its best to attempt it on a lone enemy while taking cover so that they do not attempt to attack the only other living entity (you) instead of "dealing" with themselves. As I got it myself this way, I can tell you this is a good place to get multiple achievements such as Imperial Pinball (by slamming foes on the shield generators that look like pinball arcade circles) and It Burns, by throwing troopers into the red force fields when their numbers overwhelm you with your force grip (RT). ALSO, it should be noted that leveling up Mind Trick Greatly increases the chances that your opponents will end themselves for you as well as increasing the number you can control with one attempt to mind trick!!
Good luck and happy hunting everyone.

The best area for this achievement in my opinion is immediately after the section that WilDaThril is suggesting. After leaving that area and traversing a brief corridor you should come to a narrow platform packed with storm troopers. On easy and if levelled up from a playthrough they pose little to no threat, so just continually mind trick them, and watch as they plummet off the sides. If you miss it in one go as some will attack each other, then just save, exit and then select continue from the main menu and you'll reload the checkpoint. The achievement is cumulative over playthroughs, so you just need to rinse and repeat. I got it one though, so I really doubt you could need any more than that.