There's only one questions that matters: Can I sell it? Sort your list by how quickly you can honestly answer that question. By honestly I mean multiple peop

There's only one questions that matters: Can I sell it? Sort your list by how quickly you can honestly answer that question. By honestly I mean multiple people actually paying you, or at least attempting to do so. Ideally you can do this without even making a product. Throw up a landing page w/ a price and a buy button. When they click buy, you've got intent to purchase, and you can redirect to a signup for the beta. Even better is if you have a product where you can actually take their money and just do the work manually behind the scenes. If it takes off, then start coding/automating yourself out of the loop. If not, then kill it. It's amazing how many "good" ideas just can't make any money. A lot of them you can't even give away for free :( That's your number one risk by far.