I like lashes. I have a bunch. But, prim lashes can be a pain to get adjusted. Mesh lashes can solve some of that problem. They can be more easily shaped to the avatar eye and nicely curved.
The beautiful Juicybomb has an article on lashes. Check it out: Know your Mesh Lashes.
The current main SL Viewer 3.6.7 (281793) Sep 30 2013 has the transparency problems Juicy mentions. That really sucks.
The fun part of these lashes is the tintable set and the ability to make them glow.
Update: Strawberry likes these too. See: My Favorite Mesh Eyelashes.