Here's a character I really enjoyed playing, although it was ultimately only for a couple of sessions (I don't get a chance to play much in ongoing games, as I usually GM). I played him in an Eberron game, where I first gamed with poster Blargney The Second.
Marlowe
OCCUPATION: Human Elementalist/Wandering Gambler (Mechanically, human wu jen 5)
PHYSICAL DESCRIPTION: Average height, with shoulder-length brown hair that is well-kept. Marlowe always wears a brown trenchcoat, with well-styled clothing (often black or gray) underneath. He is usually fidgeting with a specially-made deck of cards.
ATTRIBUTES AND SKILLS: Marlowe is an elementalist - a magician who follows arbitrary rules of magic in exchange for mastery over specific avenues of arcane study. In essence, he must follow certain compulsions in exchange for spell power. His particular areas of focus are in summoning and beneficial (ie "Buff") magic. In a fight, he usually goes invisible and then summons allies while bolstering them with specific beneficial spells. Marlowe will use his wand of magic missile as a last-ditch defence, as he prefers to avoid getting personally involved in physical altercations.
In addition to this, Marlowe is an expert gambler, and is a very well-known player of the Magician's Card Game, Transmuter. There are two versions of the game, Low Transmuter and High Transmuter, with Marlowe specializing in "Low Transmuter". He rarely loses. Marlowe's prized possession is a specially-made deck of cards, designed to be very sensitive to Marlowe's magic and giving him an edge when he plays (this is perfectly legal in Transmuter rules).
VALUES AND MOTIVATIONS: Marlowe generally enjoys overcoming obstacles, preferably without physical violence. He is a bit of a rogue, and has a knack for finding himself in trouble more often than not. His favourite past time is tricking and outwitting those around him - perhaps because of this, he prefers to avoid casting charm spells, as he thinks they make things "too easy". After all, anyone can charm a guard if they need to get past the gate, but it takes special skills to talk your way past.
Quite often, Marlowe will try to gain a superiority or edge in discussions, simply for the fun involved - certainly, any moneys he gains are quickly spent or gambled away.
BEHAVIOUR: Typically, Marlowe is a sly rogue. He has certain arbitrary compulsions he must follow (see below), and he tends to get angry when he's put himself in a situation where those compulsions come into play - when it happens, he feels as if he's made a stupid mistake. Marlowe tends to tease his friends. In combat, he is cool and collected, though occasionally has been called a coward due to his personal non-involvement in the fight. However, he proved this wrong when he single-handedly saved the lives of his companions in a fight against a possessed bard.
In some ways, Marlowe is a consummate liar. However, in others, he is scrupulously honest. For example, he will never cheat at cards, and abhors those that do. He will lie to a gate guard for personal gain, but would never make a lie that would harm that gate guard's career or future. Marlowe never steals (although he has no problem with bribes, small cons, and even blackmail).
USEFUL KNOWLEDGE: Marlowe knows every gambling game in existence. He is streetwise, and well-versed in arcane lore. He often has his fingers in several small-scale cons and schemes at any one time. If Marlowe doesn't know something, odds are he can summon someone who does.
MANNERISMS: Marlowe's biggest problem are the magical compulsions he has voluntarily put himself under. If he breaks one of these compulsions, he loses access to his magical abilities. There are currently two compulsions he must abide by:
1) He cannot leave a building the same way he entered it. The only exception to this is if Marlowe is in a different state of consciousness going out as he was going in. Thus, Marlowe can enter a bar, get drunk, and leave through the same door with no problem. However, he usually has to find more interesting ways to get out - including starting bar fights so he'll get thrown out a window.
2) Marlowe cannot cast spells during a storm. This is often a problem, as his main partner in crime is a member of house Lyrandar.
(Basically, "Transmuter" was a game I made up that Marlowe would refer to. The idea is that wizards are allowed to cast spells while playing it. In High Transmuter, the wizard is not allowed to use his physical body in any way to play the game - he must even use spells to draw cards from the deck. In Low Transmuter, the game has more restrictions on the spells allowed to be used. In both versions of the game, players can use spells to "cheat" - cast illusions on your cards so they are something else entirely, scry on other players, or summon additional players to play for your side. The only rules in regards to spellcraft is you can't harm any other player, and you can't dominate someone's free will).