I have one player who almost allways plays lawful, or good, and often both at once. That siad, i have three other players who, no matter what they are playing, act chaotic neutral. "Yes, i did kill that beggar, but i also fed that orphan back there, so i'm still Chaotic neutral".
"So what if the king throws a fancy-dress ball? I'm coming in my blood-stained adventuring gear. Much better conversation starter."
They also tend towards chaotic stupid.
"Oooh! A floor switch in the middle of the room! I STOMP IT!!!1!one!"
And I have one who allways plays a bard, even if she's told not to play a bard, she will replicate being a bard by becoming a multiclass fighter / rogue / sorcerer that specializes in enchantments. And now that i've shown her the beguiler i'm very, very afraid. She's ALLWAYS chaotic neural.