At the risk of sounding flippant because I'm going to give so short a post, let me quote Edna Mode from The Incredibles. "I never look back, dahling."
I'll never play any character again. Once the natural run of a character is over, and the campaign he's in is over, I don't look back--I look for the next challenge.
Sure, many of my characters are (at least mechanically) quite similar. And in terms of approach, I do also end up with kind of "shades of gray" morality. I find regular heroic characters to be somewhat boring, while rakish scoundrels are quite droll.
I don't want to cross the line and play an outright villainous character, but I do like a good anti-hero. A Han Solo from early on in his character arc, who never really redeems himself and becomes General Solo, but who just remains a rakish scoundrel. Maybe even one who falls as his character arc, and becomes more of a Boba Fett.
However, I could see playing a somewhat air-headed hero. A bit ironically. That could be fun.