STILA
Stay All Day Waterproof Liquid Eye Liner
I love liquid eyeliner, and if I could only use one for the rest of my life, this would be it. I've probably gone through 20 at this point. It's been a staple in my makeup bag since college, and I love that the formula is waterproof, richly pigmented, and easy to control. Using a liquid liner always requires some practice, but I swear it's so much easier with this one thanks to the precise, marker-like tip. I have it in black, brown, green, and blue!