I use this COVERGIRL Perfect Point PLUS Eyeliner ($6) regularly, and I love that it gives me precise control. The colour is very opaque and it stays put for hours.
"This goes on very easy, not like pencils or such that are rather hard and unforgiving," one customer explained. "The twist allows you to advance the product in tiny increments so you get just what you want, not so much that it breaks, but enough that you can control the colour."