I am always curious about the new liquid eyeliners on the market. My newest one is Maybelline Master Precise liquid eyeliner. It promises ultra thin 0,4 mm line. My favourite liquid eyeliner is L'OREAL Super Liner Carbon Gloss. My only issue with it is that it is not that good in drawing thin lines.
This January L'OREAL came out with Super Liner Perfect Slim, which is super thin, very black and easy to use. Maybelline Master Precise is basicly the same thing. L'OREAL Perfect Slim smudges a little bit at the end of the day. I don't have this problem with the Maybelline one. Both eyeliners are a little difficult to take off.