The standard, basic polish remover that you can find in like every store. Most of you pick it up without a second glance, and I did too for years. But one day i read a little further.
GELATIN! For those that aren't as crazy as me, gelatin is a gel substance that is made from crushed up animal bones and connective tissues. The should be enough for even meat-eaters to be grossed out. Gelatin is found in Jell-o, gummy candies, and many nail polish removers! So if this is something that concerns you - look out for it! Always read the ingredients.
So, upon learning this i was on a mission for gelatin free nail polish removers. I tried an organic, acetone-free one from a vegan website. But that didn't remove the nail polish at all and I was very disappointed. So I use pure acetone. It can be found at any CVS and is usually cheaper than the fancy stuff so that's a plus too. On a negative side, it can dry out my nails, however I find that a small price to pay for saving and animal's life.