For Coho and steelhead 15lb ultragreen mainline and I will run 10lb leader down to 6lb depending on water clarity in ultra green as well. I have heard good things about some of the fluorocarbon leader material and you can run a little heavier leader than with standard mono.
On a couple of the reels I use for tossing spoons I run a bit heavier mainline so as not to loose as many $6,00 lures
Centerpin 8)