If your talking actual leader material Seaguar Blue Label is the stuff I use it comes in all kinds of tests. If I am not fishing Pike I use Pline it is way more price friendly and works great for anything but pike.
I run 6-12 pound depending on water clarity and what I can get away with.
On leader for walleye and panfish I rarely go over 6 pound when I am using jig rod. On set lines if water clarity is not good and I don’t worry about fish seeing line I will use 12 pound Pline on tip ups for walleye.
I bought the blue label for Pike as an alternative to braid or steel leaders but I don’t pike fish much.