I've honestly tried all of the popular mascaras, from drugstore to department store. I've tried multiple Lancome formulas, Dior, etc, and the BEST mascara I've ever used is the Rimmell Lash Extension. It really does curl and volumize, assuming you know HOW to use mascara the right way.
It feels good paying roughly $5 for a tube as compared to $20 for some department store brand.