I chose all of the above, but have to honest here. I've never written a commercial. But I've written 1 bad novel, a novel, many screenplays and many stage plays.
I enjoy writing screenplays for the sake of directing them. At the moment, I'm not very considered with publication, distribution, money-making, etc. Maybe one day down the line I'll be "corrupted," but for now I want to sound high-falutin and say I'm just interested in the art of writing for the sake of the art of writing.
I'm surprised that few people picked write a novel -- who doesn't? Maybe I'll be the next Fitzgerald or something, although I'll probably just end up writing some garbage like The Last Tycoon without This Side of Paradise behind me.