Decisions, Decisions: Art or Commercial?

I'm starting to hate NaNoWriMo and it hasn't even started yet. Problem is, I have one crime novel idea that's very serious and character driven and a gritty noir blast. I also have an idea for a spy adventure that's a fun romp. I want to write something that I can then sell; I think the spy story will sell better than the crime novel, but the last thing I want to do is write something purely commercial that has no artistic qualities. That's what I like about crime fiction, it's commercial but not terribly so; it's the one venue where the literary novel and pulp can coexist. When I think of doing a spy story, despite some of the themes in what I have in mind, I don't think of art, I think of crass commercialism and it makes me not want to write that book. Considering I haven't broken into the market yet I should write something that stands a good chance of bringing money into the house, but part of me would rather write the book that will be more of a struggle. But haven't I struggled enough? Shouldn't I write a book that might be more readily accepted by the public? Regardless, the spy story will be done under a different name than Brian Drake. Drake does serious work; the other guy does the fun stuff. Maybe I'll have to flip a coin and decide that way.