I am terrible about eyeliner. I love it more than any other type of makeup (except for possibly mascara), so when I get it I like to buy the best I can get.
So far my favorite has been Chanel's Liquid Eye Lines in Noir, pictured below.
Another bonus is the ease of application. I am not very good at liquid liner, so I have to get in there and get the job done in one fell swoop and hope I don't smudge before it dries. This is very quick drying, which made it became my total go-to liner almost right off the bat. The only downside to the quick dry is if you mess up it can be tough to get off without a really good eye makeup remover (water doesn't do the job, obviously), so keep a good remover and cotton swabs on hand for any accidents.
If memory serves right, this retails for about $32 a bottle (holy high-liner, Batman!), but it is one of those products that I think is worth every penny. Mine lasted me quite a while, about six months or so with once or twice daily application, which makes me consider it a good investment. Keep in mind I wore this stuff during my 'gother than thou' days, so I caked it on, haha.
I have yet to find any drugstore brand that even compares. If anyone knows of something that does compare, please let me know. Seeing as I'm a full time college student on a limited income, I am unable to splurge on my favorites like I did when I was working full time.