Find yourself a good LBS with a variety of bikes. Take a bunch of long-ish test rides (3-5 miles). Buy the one you like.
So much depends on your condition, your flexibility, what you're used to, how each bike fits you, and (pace car salesmen) even how you like the color, that nobody on the interwebs can buy you the best bike except by random chance. The best bike is the one that you like to ride, period. The second best bike, if you don't like to ride it, may turn into the worst bike because it takes up space in your garage. That means, ultimately, you've got to go pick it.