The Chanel stylo yeux waterproof liner has long been one of my holy grail items. A twist up eye pencil, they never need sharpening, go on smoothly, and last all day. Whilst they come in a variety of colours (the turquoise is nice for the summer), my favourite is black.
These retail at £19, which isn’t cheap, however I use mine every day and it still lasts a good 6-8 months. I would repurchase this again and again without a second thought.