I've recently gone from Elixirs to D'Addario EJ-16's and EJ-17's. I've really liked the change, both in sound and feel. I agree though too with what Steve says about the strings that the guitar comes with, and I do like the sound of Elixirs on Taylors (at least the ones I've played). They seem to complement each other well and they definitely last a long time (referring in the latter to the strings but yes certainly the guitars too). I think I'm just finding that I like un-coated strings a little more. There was another thread on guitar stores recently. I don't know much about how guitar stores operate or what their profit margins are other than I like 'em and want to see them stick around. I recently bought a 10-pack of EJ-17's on Amazon for a great price but I don't know... I think I'm going to start buying them from local stores again after these run out even if they cost a little more, whenever I can swing it financially. I do buy guitars and other guitar-related things from local stores but I also get to sample a lot of different guitars, whenever I can and want to, on their dime -- regardless of whether I buy anything there. That's a pretty cool deal. I'm not saying that my string or other accessory purchases make or break a store obviously, but it can help a little. OK rambling and off-topic I know, just came to mind as I thought about strings and my recent Amazon purchase.
-Brian