The Legend of Zelda: Ocarina of Time Glitches

Unlimited Gold Skulltulas
When you are a kid head to Hyrule Castle grounds and there is a grotto by a tree inside the fence corner by the castle (near where Talon was sleeping). When you open the grotto using the Song of Storms go inside and you will see a skullatula on the wall. Now comes the tricky bit.

Kill it and then position yourself so you're facing the token but have your back to the exit platform. Use your boomarang to grab the token, but right when it strikes it backflip onto the platform. Link should grab the boomerang and token exactly as he is warped out. When you press start and look at your Skulltula Count it shows you got it and when you go back down it should be there again.

This can be repeated as often as you want as long as you get the timing just right.