Finally I'm getting the chance to actually ROLEPLAY instead of DM tonight. I'm a bit rusty, to be honest, and for some reason I've chosen to play an extemely challenging character.
Here's the gist: he's crazy, but not LOL RANDOM MONKEY ROBOT crazy. Think subtle, interesting, devious. Health Ledger's Joker and Dexter mixed up somewhat.
His skills are all about manipulating people, pretending to be someone he's NOT, and, kind of ironically, being able to read other people's motivations and detect lies.
Anyhow, I'm looking for inspiration. Googling this on the internet yielded results mostly for text-based RPGs, which isn't necessarily applicable.
So, my question to you is.... in your experiences, what made a good (interesting and fun) insane player character?