I've searched high and low for a deep dark blackest black. When it comes to pencil liners, Feline is even darker than Smolder in my book. I just can't get it to stay on me with smudging, and smudging badly. If it didn't smudge I would never buy another black liner.
I've compared MUFE and UD Zero to Feline and they aren't as dark. My skintone is chocolate *smile*, so when a black liner pops on me, take it seriously.
Until I can figure out how to get Feline to stay, I use Prestige Total Intensity. It is black and it stays, on the lid and waterline.
Pencils : MAC Feline & Smolder (And I'm not a MAC is the be all/end all girl either). I've tried UD Zero, and the MUFE liner- both brands I love. They are great but not as dark, I promise you. Neither is the Lancome liner. Prestige Total Intensity liner is a great alternative for an even better price.
When it somes to liquid liners, Lancome Laque is a dark, glossy black. Usually liquids have that shine until they dry, but the Lancome has a pretty dark shine to it. I layer it over my gel liner occasionally, and you know gel liners are super black.
The other super dark liquid liner I've tried came with Loreal Telescopic. It is a felt liner, and it is wicked black! I really miss it. MAC's Rapidblack liner and Chanel's liquid liner aren't as dark as the Lancome/Loreal ones.