My favorite character, hands down, would have to have been Isabelle on Tenebrae. I had never played a game with dice before, knew nothing about D&D, so I set up a rogue with high social skills figuring I could be a gather information character. Everyone made fun of me for setting up a useless rogue.
I even took Run as a Feat, guys. I took Run. I admit it.
She ended up being one of the most powerful characters on the game thanks to sneak attack specialities at higher levels that took away...I don't even remember. Strength? Con? And then a sword of wounding and a luck blade. She could talk her way into and out of anything. She was completely and totally out for herself and had very little loyalty to anyone. She wouldn't help if there wasn't gold attached to something. She had an insanely high gather information and even though she was a complete bitch, she'd give out information to people (in a mean way!) to get them into plots. She started up an investigation company with her friends (which was really just a way for me to run PrPs for newbies and get them involved in the game before I was staff) that hired contractors, took over the thieves guild at one point, and got roped into saving the city way too many times because she considered everyone else utterly incompetent. She was a leader who didn't take shit from anyone and would call people out on their stupidity instantly. She eventually actually took Leadership and got a baby dragon companion named Havelock who was super polite and called her Auntie, but was otherwise utterly useless cause he was a baby.
There are three stand-out scenes that come to mind:
The Saluven plot, which was one of the better meta-game plots I've ever seen run on a game anywhere (props to Maelstrom!), which was the culmination of like, years of plot pieces moving around before I was even on the game. Isabelle thought she'd figured it all out (she had like 9 of 10 pieces put together!) and went to confront a big NPC with what she had and WHOOPS that 10th piece? Was that that NPC was the bad guy who turned her into a statue and then went about amending his plans based on what the heroes knew. It was so awesome! One, because I was totally blindsided and thought I'd done such a good job of putting it all together (I figured out the secret plan, just not the secret person at the head of it!), and two because Isabelle was insufferable and it was totally humiliating. EVERYONE knew. Everyone! It was great.
During another big City-Is-Under-Siege-Why-Does-Anyone-Live-There plot, I was trying to keep Isabelle out of the Big Plot so that other characters could do things and had her follow up on a different plot where a rival thieves guild that was trying to take over instead. She got "caught" by the leader of that group and they demanded she take them to her Guild, since they had been unable to find it, so that they could raid and slaughter everyone.
She agreed and then led them to the main headquarters of the NPC bad guy for the Big Plot and they all got murdered. I was so proud. The staffer running the scene was like "...this wasn't even something I had considered could happen." So the alternate-guild was wiped out and it helped spawn a scene for lower PCs in the Big Plot (big plots being "solved" by only high level PCs was ALWAYS a big peeve of mine) with a weakened NPC villain.
There was a point where the game could've had a kinder, gentler Isabelle. She was totally and completely in love with her business partner and best friend, who was a Good Guy and completely mitigated her bitchiness. I mean, she was still mean to him, but she was less cruel than usual when he was around! But she never said anything, they never really acknowledged it or talked about it, and he fell for someone else. So she was like OKAY FUCK THAT and went all in on greed and any "love interests" she had (sorry guys!) were purely to advance her social standing and treasury.But she was probably one of my best realized characters, super fun to play (though admittedly hard to take), and if you could stand her for five minutes she'd send you off into All The Plots. Her investigation agency would hire new players, which gave them access to PrPs we'd run for the company (just your average go kill some kobolds/guard a caravan) and also any plot information for things that she'd get from the many, many, MANY legworks I'd do.
She was great and I totally miss playing her.