Sometimes some have brought up the idea that even if your characters aren't you, there's still a little bit of you in every character you create. I can't say whether or not this is true for everyone, but I believe it's true for me.

There's also been talk about their physical appearances... if the characters resemble each other physically.

I wonder, for those of you who have played multiple characters, do they tend to have something in common? And if so, what is that, and do you know why?

...Because it recently struck me that my characters tend to have a lot of pride, and even my 'bad' characters have some sort of honor. And that playing a character who has no pride might be interesting, for a change.

I also struggle to do bad/evil things and break laws in the game (because I don't want to get caught or make people angry with me).
The exception is when I played the Dark Brotherhood or Thieves' Guild and was supposed to break the law.
That's part of the reason why I created a bandit, and still, she's not really an evil person.

Alchemy and sneak, regardless their class.