Promising review: "I don't usually write reviews, but I had to rave about this eyeliner because it's amazing. My go-to eyeliner used to be the Kat Von D Tattoo liner, but this is my new favorite. I think the quality is even better overall, plus it's at least $10 cheaper. It basically fits all of the requirements I would want in my perfect eyeliner. It's affordable, extremely black, opaque, easy to use, waterproof, stays on for a long time, and the tip is quite thin so you can get wings as sharp as a sword. I also usually have to use makeup remover and concealer to clean up my lines, but I barely need to do any maintenance with this. My cat eyes have been turning out so clean and beautiful." —Caiti

Get it from Amazon for $6.29.