My favorite MAC mascaras are the Plushlash and X. I also like the Studio Fix Lash, but on its own I find it weighs my lashes down, so when I want more drama, I'll layer it on top of Plushlash for super volume, fullness and length!
I am very excited for Opulash. We have the brush on the displayer at my counter, and it's HUGE! Very similar to Diorshow and BadGal Lash. Hopefully they will have a tester to try it out at the next update!