Dead Space 2

The first time you really get the chance for this is at the beginning of Chapter 2. After using/passing the Save Point, your locator will direct you to the Titan Height Apartments.

As you open the door, a Slasher will appear at the end of the hall and come running at you. Take him down quickly, before you move forward. When you do move forward, off to your right through some debris, you will see an Infector changing a dead body. Grab the spike in front of you on the floor with your Kinessis, aim, and launch it at him. It must go at least 17 meters, and it must stick.

The video below should help explain it more. I think they are on easy though, because it took more than one shot to kill the Slasher, and it took me several tries to hit the Infector just right. Their rig is the first rig you get in Chapter 1. Again, I think there were on easy just to figure out how to get the achievements - there was no upgrade. As I stated above, it took me several tries to hit it just right, and I was playing on normal. If you mess up, just reload your checkpoint.

If you have a problem getting it here, wait until you get the Javelin Gun, and you will get it. There were multiple times where I sent a baddie flying with it at long distances.

Credit to Achievement Hunter for the video upload.

If you don't mind waiting until later in the game...

***SPOILER ALERT***

I got mine in Chapter 10 while making my way down the Ishimura tram tracks (long open corridor where you first encounter enemies). After the fight with the Brutes, Ellie will tell you enemies are pouring into the ship and Necromorphs will burst through the floor grates in front of and behind you. Allow an enemy to get close, stasis it, and with your TK or Javelin gun, position yourself so that you're aiming a direct shot down the corridor (for desired distance) and towards one of the sides (so it sticks), and let 'er rip.

Another good point for this is chapter 11 in the mines, when you enter the cave where you need to replace the power junction, as soon as you enter a black necro will drop down from a vent, kill it and quickly move to the end of the corridor, if you turn left you will see another necro running towards you through a long bridge, stasis him and with the arm of the previous necro or with the javelin gun just shot aiming to his torso and he will fly the distance to net you the achievement.

The good thing about his area is that there is asave station right before crossing the door so you can just repeat if you did not make it.

i got mine in chapter six just after you meet the girl, go up the lift walk passed the save point and a necromorph and a big fat thing will come running at you, use the javelin gun on the necro the first shot should slow it down and then just before it gets to you aim for its stomach and sent i flying down the corridor

Very easy, simple place to get this is in the church in Chapter 5. It is the same large room where you get grabbed and then attacked by the pack from the demo for the game. when you proceed up the ramps and to the door at the center of the second floor, a necromorph will always climb over the balcony behind you. Just be ready for him with a talon, javelin, or spear you find laying around and hit him as he is climbing up. Pretty much guaranteed to send him flying across the church. I need this with a talon i grabbed off a dead necromorph on my way up there. Happy hunting!

During Chapter 1 after you have acquired the Javelin Gun, you will come to a save station in a section of apartments. The path to progress will be in the opposite direction you face for the save station, if that helps. As you leave the save station, you will pass a closed gate on your right, and behind it there will be a woman crawling along and crying, then she will die. As you head towards the exit, a necromorph will break through the wooden door on your right and attack you (of course).

Run towards the save station and when the necromorph reaches you, run back to the exit quickly, then when the necromorph reaches you this time, shoot it with the Javelin Gun. Make sure your angle is right so it hits the other end of the hall. The reason you must be at the opposite end from the save station is that I don't think the necromorph will stick to an exit door.

I know it's a little wordy, but I hope it helps.

Another good spot for this is in chapter 2 after you get the train moving.

Fight off 3 or 4 enemies and make your way forward through the train.

You will come to a section with a car missing and you have to fly Iron man style to the train up ahead. As you move forward a slasher will emerge. Shoot off his arm and grab the arm with LT+B with Kinesics and allow him to draw close then blast him in the head/torso with it. He should fly to the back of the train and stick.