I recently had the chance to play one of my favorite characters,
a chaotic evil gnome bard named Krishni in a good/neutral group.
Krishni loves heroic stories and desires nothing more then to be a hero, but deep down he is a violent being that is fascinated by bloodshed and murder.
What hinders him greatly is his abysmal strength (GM allowed me to have 6 strength) and his poor judgment (8 Wisdom). And while he does want to go on adventure with the good guys (hes one of them, after all), he will use every opportunity to make the story more heroic - the dire the situation, the greater the glory.
His grandmother taught him to never punish the good guys, so tries to keep his urges down and saves them for the bad guys, but if someone "proves" that he is a bad guy (for example by not helping the group), he is very willing to use magic and deceit to solve that problem.
It worked out pretty well, because Krishni absolutly adored the groups Barbarian and Fighter (they look like the kind of hero Krishni would like to be).
If the group (5 players) decided upon a course of action, he would try to persuade them to do the "good" thing, but he would not impose his will (openly) - after all, he found a group he felt comfortable with and admired.
My favorire moment was, when the group headed to one of the citys finest establishments to ask the owner some questions, and the guy at the reception didn´t want to let them in, even after Krishni loudly proclaimed that they are the heroes which would save the city.
In the evening he decided to punish this man and created an illusion of him and went to another local bar where the illusion called the owner a dick and that he hated to work there. Needless to say, the man lost his job, and Krishni had suceeded to punish another evil guy.