What's Your Line?

One of the most overlooked aspects of the flyfishing gear equation is the fly line itself. The more I fish, the more I'm starting to think that the line is as important (or more so) than the rod you cast it with. You can have the slickest "cannon" in the world, and if your line is sub-par, you'll be shooting duds.

Does anyone agree with me here? What lines do you fancy and why? I'm loving the SA Sharkskin, especially in the WF 5F variety, though I've heard people complain about the noise it makes. (As far as I'm concerned, the thing can whistle the Brady Bunch theme, so long as it rides and shoots like it does.) I'm also big on the RIO XS lines. Heard nice things about Air-Flo, and a new Cortland model.

Do you put a lot of thinking into the taper and model of line you use? Can you tell the difference between lines when you're casting dry flies, versus nymphs, for example? Anyone still addicted to double-tapers? Do you clean and care for your line, or do you (like me) think, "Jeez, for $50, $60, even $100, the dang thing had better walk on water, and last me several seasons?"