I happen to have 4 MAC Chestnut lip liners in my collection. I'm a hoarder that way. Many of them are years old, replacements of lost pencils (that I later found) etc. And then, low and behold, I stumbled upon NYX lipliners. I'm almost positive I bought my first one at the beauty supply store when I was stocking up on false lashes. I'm not crazy about everything that NYX makes, but these are spot on.
MAC Chestnut lip liner is that staple chocolate brown liner that goes with 70% of the lip colors you own. People wear it alone, sometimes with clear lip gloss, also with other tans and beiges. 9/10 someone is going to try and sell this to you. It's truly perfect for brown skin.
They are almost identical! I use them interchangeably. Expresso is a hair lighter, but when you're wearing it on your lips, you can barely notice. One thing is for sure, I won't purchase another Chestnut!
You can purchase them via nyxcosmetics.com here for $3.50, but they are $3 at my beauty supply store.