How to delete objects stacked on top of each other? I made a textured coin using this tutorial and when I tried to duplicate it, it made an infinite amount of coins stacked on top of each other somehow. 

I've already tried to delete them individually. It's not working, there's just so many I don't know how I did this.

So how do I delete all the coins which have stacked on each other?
It's hard to tell exactly what you've done with seeing some images or the blend file. 

However if you press "A" twice to unselect everything, then select the coin you want to keep and press "Ctrl + I", Blender will select everything else and unselect the coin you want to keep. Then you can press "X" to delete everything else in the scene.