I always liked playing the bad guy when we kids were cowboys. The bad guy didn't have to play by the rules. If someone accused me of not being fair when I ambushed them, my response could be, "What's fair? I don't care, I'm the bad guy!" At least it was fun until my sister got mad and threw a broken toy gun at me. The ragged edge caught my cheek and left a nifty triangular scar that lasted a good many years.
I still find the bad guys more fun, and easier to "play." Am I warped? I have a character in my current novel who is full of herself and bad tempered. A lot of what she says is mean spirited and sarcastic. I love her! She says a lot of things I have thought of saying to people, but am too nice to say. And my niece said something really horrible recently that was so funny I'll probably put it in my character's mouth, too. A good line is a good line, if it's in character and advances the story, and I have the perfect spot for that line.
My heroine has to be a better person than that, but not completely good, or she'd be a total drag. Nobody would relate to her. So I also get to enjoy "playing" her bad side. And when she's good, she's so conflicted that I'm beginning to find that fun, too.
Playing make believe is a truly wonderful pastime for kids or adults.