Wilson Fisk—Kingpin

The exceptionally strong criminal mastermind, known as Kingpin in the comics, is probably one of the best villains the MCU has put out thus far, even better than Loki in my opinion. To be fair, looking at the villain's roster thus far, it may not be saying much, but I thoroughly enjoyed everything about him, and Daredevil in general.

EDIT: Now that's Season 2's dropped, I've decided to create a set of patch notes for more recent characters. You can see the changes that I've made here.

Name: Wilson Fisk
Race: Human
Experience: 60 (Heroic)
Power Level: Pulp Hero (15 PP)
Agility d6; Smarts d8; Spirit d8; Strength d12; Vigor d10
Pace 6; Parry 7; Charisma –2; Toughness 10 (2)
Hindrances: Cautious, Dark Secret (M), Loyal, Ruthless (m), Vengeful (M), Wanted (M)
Edges: Arcane Background (Super Powers), Berserk, Brawny, Filthy Rich, Combat Reflexes, Brawler, Take the Hit, Charismatic, Connections, Frenzy
Skills: Fighting d10, Intimidation d10, Knowledge (Crime) d10, Knowledge (Mandarin) d6, Notice d8, Persuasion d10, Streetwise d6, Taunt d4
Inventory: Personal Body Armor (Armor +2, torso only)
Powers:

• Super Attribute (8): Strength +2, Vigor +2.
• Super Edge (4): Combat Reflexes, Brawler.
• Super Skill (3): Fighting +1, Intimidation +1, Persuasion +1.

Wilson Fisk was born in the late '60s to a cruel and ambitious father. Bill Fisk ran for the Hell's Kitchen city council hoping that it would make him rich through bribery and corruption. When Bill lost the campaign, he took his son to beat one of their neighbors for bad-mouthing him. Bill's drinking became worse and worse, forcing Wilson to stare at a blank wall as Bill beat his mother. Once Wilson had finally had enough, he took a hammer to his father and murdered him. After disposing of the body, Wilson was sent to live with relatives, and then further left to Asia to live abroad for many years.

After the Battle of the New York, Fisk returned to New York, taking advantage of the destruction of the city by the Chitauri to build a criminal empire with the help of the Russians, Japanese, and Chinese drug trade and sex trafficking businesses. Fisk built a reputation of absolute fear and terror within the criminal underworld, while using his money and influence to control the politics of the city from behind his veil, using his best friend James Wesley to communicate with the world.

More than two years into his dominance in Hell's Kitchen's underworld, Fisk met Vanessa Marianna, the future love of his life. Around this time, the Russians began to have trouble with a masked vigilante, but Fisk ignored this small nuisance to have dinner with Vanessa. Unfortunately, one of the Russian brothers, Anatoly, decided to approach Fisk and ask for his help personally. During the dinner. This led to one of the most gruesome decapitation-by-car-door events in the history of anything.

Fisk, at this point, began to deal with the others himself. He organized his other crime families to take out the Russians, simultaneously putting a target on the head of the vigilante that had been causing trouble recently. Soon, however, Fisk became even more enthralled with Vanessa, letting her in on the operations and influencing his actions within the underworld. While Wilson still held utter control, he finally came out publicly as a saviour of the city, ensuring that the people were on his side so that nothing could touch him.

The other members of his operation had their concerns, however, and an attempt was made on Vanessa's life. Fisk was enraged, but stayed at her side while Wesley left to try and take care of their newly minted loose ends. Wesley was killed later that night. This drove Wilson's paranoia through the roof, severing ties with almost all of his lieutenants and killing his chief financial adviser. Shortly afterwards, Fisk's history was ousted by one of the former crooked cops under Wilson's control, sending his criminal empire tumbling down, leading to his arrest. His influence, however, did not stop there. He was broken out by contacts within the F.B.I., and almost transported to an escape helicopter before being intercepted by Daredevil, and in their final showdown accepted the monster that he was before being beaten down by the vigilante.

Fisk was then brough to the Ryker's Island prison facility, where he's remained for months. Working with his lawyer, he has both been funneling his own funds into growing a criminal enterprise within the walls of the prison, buying off inmates and even guards, and working against the other, larger gang.

As he managed his funds and power, he heard of a man outside who was systematically murdering other crime bosses. He arranged with one of his guards to tell Castle to throw the trial and meet him inside the facility, and engineered both the assassination of his rival and Castle's release, under the notion that Castle would continue working to eradicate the criminal element.

He was later visited in prison by Matt Murdock, the lawyer that worked to bring his empire down to begin with, and after some banter, broke his chains and beat the shit out of Murdock, but not before taking a solid punch to the jaw. It is heavily implied that Fisk realizes that Matt is actually the hero known as Daredevil, and is already working on his plan on how to dismantle the lawyer's life as soon as he escapes.
—DoctorBoson