choosing next stand-alone project

Getting back into writing after a hiatus, I was spurred forward by one idea, which had some potential, but then I spent some time looking at concepts I'd been batting about when I quit writing, first chapters I'd written, and my "ideas" files and found much better ideas to tackle. I thought, "wow, that's a cool first chapter and I haven't even gotten to my favorite character yet," and "oh yeah, I've always wanted to write that!" and "before I die, I must write this one."

So now I'm confused about which to write.

When you aren't writing a sequel or novels in a series, how do you decide what novel to write next? Have you ever had the experience where at least three of your ideas pulled at you equally?

In my case, with no published novels but two marketable ones sitting around in two genres, I know I have the luxury of choosing genre, not having to nurture a career. Of the three that look best to me, one is mainstream, historical-family saga, one is mainstream, contemporary feel-good coming of age story in a small town with oddball characters, one is horror in the same sub-genre as The Stand with potential for a sequel. I'd say the historical would take longer to write, but the bulk of research on it is already done so all three look like similar length projects.

I'm not asking you to tell me which one to pick (though you can tell me which genre appeals to you more--I certainly won't be offended) but more about your own decision-making process when you're in this choosing stage.

Good advice, and thanks all. All three ideas have some outlining, but I could sure get back to those in a more active way and see if something ignites. I like the one-per-day concept, rotating until such point as I really don't want to rotate away from one. And I like the idea of immersing myself in a genre, which would be a fun way to look for a direction. (Just can't lose myself there as a form of procrastination. Must limit that to evenings, my low-creativity hours.)

I also did, between OP and now, something I normally would not do and that's think of marketability, doing a touch of research on how many books are published in each subgenre, which makes the historical/saga idea come out ahead. I wouldn't use that as my primary reason to write a novel, or to generate ideas, but if I'm still stuck by the end of our holiday weekend here in the US, I may use that as a tie-breaker.

I certainly have lots of room for improvement as a novelist. And every novel outside of formula genre is plenty of challenge for me just by being long and complex. If I have to write as many of them as I did short stories before I got competent enough at that form to sell regularly, though, I'll be dead before I'm good, so let's hope not.

And thanks for reminding me, AlwaysJuly, that these are definitely the kinds of "problems" we should wish to have.