This MAC product is the best eyeliner I have found. It goes on smoothly, stays on, and comes in a lot of colors. I also think the price is quite reasonable, as it lasts a long time.
A blogger convinced me to get this and I'm mad I didn't do it sooner. This makes my eyeliner quick and easy. It is hot and humid where I live and I never have issues with this smudging or smearing. I will never go back to an eyeliner gel pen!