Upper front strut mount.
To prove it you can have someone turn the wheel while the car is parked and you should hear the thunk up top with the hood open.
New mounts are fairly cheap but can be a pain to change if you don't have a spring compressor. Sometimes a quick strut is the easiest way to go since you get a new strut and spring however they are a little more pricey than just a mount.
Also for future reference, to check for a bad ball joint, jack up the car and hold the tire at 12 o clock and at 6 o clock and push/pull to check for play. If there is excessive play then it's likely the ball joint. If someone else is moving the tire you can get under the car and see if the ball joint is moving. Make sure it's this and not the wheel bearing since a bad wheel bearing will have play in any direction.
To check for a bad tie rod you can jack the car up, hold the tire at the 9 o clock and the 3 o clock spot. Push/pull again and if there is play it's likely the tie rod. Again, make sure it's not a wheel bearing.
To check for a bad wheel bearing you can hold the tire at any 2 spots and push/pull again. If there is play it could be the bearing. Bad bearings are usually found when they start to get noisy.