I just want to point out one irony to you, Jake. Two of your favorite novel characters a cliche's...Drizzt is a good drow elf. Artemis is a deadly assassin with a dark past and is equally as cunning as a drow.
Just wanted to draw your attention to that. But as you said, they can be quite fun to role-play every now and then.
Here are a few more I can think of:
Diversity: Character's that reflect ones personality and looks are ok in some, but not in a lot. It took a while for me to figure that out. I would spend an hour developing a guy that was simpler to me. Why? Cause I didn't want to put the hard work into challenging myself. Instead one should try to rp a character that doesn't reflect yourself, so therefore it's more challenging because you have to think what the character would do and not yourself.
Character Creation: There are a lot of crudy characters. To name some of mine: Johann, Johann, Johann, John. Yes they all are the same thing...but they were different guys. One don't name each of your characters by the same name. I found out how rediculous it is. Two, this goes along the lines of what TAD was saying. The easiest way to find out if your character is good is look at your profile, read over it. And see if you'd want to read about it in a novel. If you wouldn't, chances are it isn't very good.
I have a few other ones but they're boarding flaming...so...I can't add them.