Source: marvel.wikia.com

9. Mr. Negative

I figured I should throw in at least one post-Brand New Day Spider-Foe. As the first and most enduring, Mr. Negative earns that spot.

Martin Li was a member of Chinese gang The Snakeheads until he was kidnapped and experimented on, along with teenagers Tyrone Johnson and Tandy Bowen. All three became linked with the mysterious Darkforce Dimension and came away with super powers. Tyrone became Cloak, Tandy became Dagger, and Martin became Mr. Negative. He was split into a good half and an evil half. Like Two Face! But with cooler looking minions.

He and his devil-masked minions – known as the Inner Demons  attempted to conquer the New York underworld with a bio-weapon called The Devil's Breath. Negative battled Spider-Man for a while, until Norman Osborn took control of SHIELD and appointed The Hood as the new lord of the New York City Underworld. Negative didn't like this and went to war with him.

When last seen, Mr. Negative was loose in China, attempting to conquer Shanghai while being pursued by Cloak and Dagger.