I have a lot of characters I love, some of whom I return to again and again like Oddric, but by far the best character I have ever played is the one whom I shall never play again. His name was Thaddeus Black and he single handedly shaped the one and only Deadlands campaign I have played in.
The short version of his backstory is he was raised a wealthy minister's son but he was afflicted by curious and bad luck that caused a number of strange occurrences and the townsfolk, a highly violent and superstitious lot, accuse him of practicing black magic and formed a lynch mob. His father sacrificed himself to the mob and Thaddeus fled. Later he met a man who gave him a book that promised power if one was willing to gamble and Thaddeus became a huxter. In a cruel twist, the evil spirit he formed a connection with, the creature trying to steal his soul and take over his body, was the tormented and twisted soul of his own father.
Thaddeus was built to be incredibly uneducated, mediocre at anything involving combat, and weak as a kitten. His only gifts were a cunning mind sharper than the throwing knife he could barely use, an iron will that could shake off any shock or horror, and a superhuman (literally, according to the book) amount of charm. He was the archetypal charming bastard. And boy was he a bastard.
In his first session he convinced a young man who had watched his brother die to dress in drag (badly) and strap dynamite to his chest in order to seal away an ancient evil while Thaddeus and his companion bravely rode out of town in the opposite direction. In his second session he stole one inventor's sleeping potion, fed it to another, and tried to pass the internal combustion engine off as his own design. In his third session he hired another PC to be his muscle for a fraction of what the quest reward would pay, then later when the GM sent hired killers into his room he woke up and convinced them they had the wrong guys and went back to sleep. In his fourth session the GM sent a powerful assassin, a character designed to kill one or more of the party, after him but he wrote a song on the fly that caused her to attack him on his terms, somehow evaded all of her attacks, and seduced her so powerfully she became his companion for the rest of the adventure.
The poor GM kept trying to build intricate plots for us to navigate but each time we would (gleefully, I'll admit) circumvent his designs, often when our amoral characters simply declared that whatever badness was going on they wanted no part of and would just ride out of town. Because of this whole cities were destroyed through our inaction and we had no idea why or what the actual metaplot of the campaign was. We were too busy killing a man because he'd made a perfect utopian town but had pissed us off because we couldn't loot any of his illusory wealth. Or getting in a fight with Russian cyborg men and Thaddeus once again convincing one of them to join the team by breaking the poor man's mind with charm and "logic". Or fornicating in the remains of a man I exploded. Or taking over Boise and turning it into our own version of paradise complete with taco stands and a giant golden statue of the man whose name they bore (not me, that would have been Don Diego del Taco.)
At one point in our attempt to claim Boise as our own we got in a heated firefight and Alvira suffered a serious wound and went into a coma. The man who did it... did not die well. Thaddeus was beside himself. He sought out the best doctor he could find who, luckily, was mystically inclined and said her soul was trapped. Giving cryptic orders not to be disturbed Thaddeus locked himself in his room and laid beside his beloved. He followed her soul to the Chinese heavens where a Thunder God was claiming her as his new thrall. Thaddeus challenged the mighty god to a duel, calling him a coward if he did not accept but then agruing it would be no fair contest for a god to fight his puny mortal form so he should be allowed a champion. When the god accepted Thaddeus called upon the one spiritual being he could, his father, and he said the words that hungering spirit had been waiting years to hear: "Take my soul."
Soulless Thaddeus managed to outwit his father and keep his mind his own but he took a darker turn. He attempted to orchestrate the death of one of the PCs which only failed because that character had actuially been planning to betray Thaddeus for some time. But later Thaddeus went through a spirit journey, facing his own demons and trials, and he regained his soul, now purifed. Suddenly he was a much nicer person, though wracked with guilt and horror over the deeds he had committed.
He sought to make the world a better place, even seeking to make amends with his former enemy. They met at a presidential ball but only Thaddeus and his companions were unaware this would be the pivotal moment in history when the third party, the organization we'd basically pissed off and run from the entire campaign, would make their move. Amidst huge plot reveals, dopplegangers, zombie (anal rapist) Abraham Lincoln, and a full on ritualistic massacre Thaddeus and his companions fought to save the world by destroying a nearly immortal clone of the most important man in history. That was when Alvira was shot in the head. Thaddeus held her as she died and when his next turn came I quietly explained each methodical action. He stood up from behind his cover and walked into the clear. The enemies fired round after round of bullets into him as he cast his last spell and fired a mystic bolt - and here the dice blessed me by rolling insanely high damage - not into the doppleganger but into the man we'd sworn to protect. As he fell back, arms out in a Christ-like pose and cards streaming from his hands like falling leaves, the GM sat in silent shock. Even his endgame had counted on the man living. With that man dead the world would end. But that was what Thaddeus wanted. His world had ended with Alvira's death and he would be damned if he didn't get one last say in the matter to end the game on his terms.
Never did I expect to play through such an emotional and powerful character arc that fit so perfectly with where and how I wanted a charcater to go. Never again will I ever play Thaddeus, the man whose sardonic southern drawl I still hear in my head to this day and would dearly like to let out once more, because nothing will ever live up to that perfect story.
My worst character would not have been so bad had he not been brother in arms and faith to two other members of the party. No need for the long story on this one. Basically we accidentally formed a party dynamic where the frontline muscle characters always stuck together and bullied the others into doing what we wanted. I do maintain the DM made some mistakes in how he dealt with the problem but myself and the other two were the initial problem and for that I still feel bad for making the game less fun for others. The character's name is lost to time but I do remember he was a Shifter battle-cleric in the early days of 4E.
I've already mention Oddric, the orkish rogue who I have rolled in every tabletop system and computer game that'll let me do it, Tgudd Grizzleyback, the bear-riding dwarf is fantastic in concept though he's had only one actual play session. Legerdemain, master of magical fire and whose likeness is my avatar, is basically my Mary-sue character and proved a decent PC but a much better archvillian for a campaign I ran. Lastly comes Biskik who is technically a DMPC but who is a ton of fun to play and well beloved by my players.