Try Dior DiorShow Blackout Mascara, it is definitely the blackest mascara around. The brush easily coats lashes for length, volume, and curl; I really recommend it! One of my favorites.
Answered[ Edited ]
I agree with sbasta's recommendation -- YSL Faux Cils (try Noir Radical) and YSL Faux Cils Shocking (in Deep Black) are excellent options. If you were not looking to spend that much, I would try Too Faced Lash Injection (in Pitch Black) -- it leaves your lashes super dark, full and volumized (it's a tubing mascara).