I am a little bit of all of them. Depends on the situation and my mood at the time. Sometimes I create characters who would be munchkin like, sometimes I do them for role-play value, other times I like to make a character with a tactical advantage.
And playing them varies as well. Sometimes I feel like fighting an endless horde of kobolds, other times I just want to role-play and further the story that way. Solve puzzles, riddles, learn about the history of the game world, who can and can't be trusted, those kinds of things.