Most Economic Way to Get a New Smart Phone

So I have been thinking about what to do when the contract for my cell phone is up. Most important thing to me is to get the best phone that I shall be able to afford to have, but without getting tied up in some sort of contract that makes it so I am stuck with the same phone and the same provider for the next three or four years. I sort of think that I should get a phone and learn how to jailbreak it, but that is a bit of trouble to do and there are apparently risks involved in it right now. I do not really know that much about freeing phones from the restrictions that the cell phone makers and cell phone service providers impose upon them, but I certainly like it as an idea. I do not want the maker of my cell phone to tell me how I should be using it, that seems like it is not really any of their business.