With Halloween coming, I've been using a TON of black polish. My favorite is Sinful Colors Black on Black, and it's the one I use most often. I typically don't even bother to put it away. But I do have several other bargain black polishes, so I thought I'd do a quick run down to see how they compare.
In all photos, polishes shown are, L-R: Sinful Colors Black on Black, Wet N Wild Black Creme, Wet N Wild Fantasy Makers Black and a Fright Night Claw Polish mini I picked up on clearance after Halloween last year.
This is one coat of each. The Sinful Colors comes closest to opaque in one coat. I was pretty sure the Wet N Wild and Fantasy Makers would be the same polish in different bottles, but the Fantasy Makers was more opaque and less streaky in one coat than the standard Wet N Wild. I have no idea why the claw polish is so matte on one pass, because it shinies up nicely with subsequent coats.
Two coats. The Sinful Colors is good to go, the Wet N Wild is still a bit streaky, the Fantasy Makers is probably good enough (especially as a base for nail art or a layering color), and I think the Claw Polish is good to go as well.
Three coats: The Sinful Colors and Claw Polish didn't need it, but I added it for consistency. The Wet N Wild and Fantasy Makers are good to go at three coats.
For fewest coats and smoothest application, Sinful Colors Black on Black is still my favorite. The Claw Polish surprised me, as it was in the costume makeup section, in a two pack, for something like $2 to begin with. Too bad it's only a mini. The Wet N Wild and Fantasy Makers required an extra coat, but I don't think that one coat is going to make or break me. I will definitely always go back to Sinful Colors, but maybe I'll use up these two before I repurchase it.
Hope this helped you out a bit!