I'm using 12lb Berkley Nanofil with an 8lb fluorocarbon leader.

*
+1 I like the nanofil!! Good stuff!

If you use Fluoro for your main line you better use a swivel with a spinning reel or you will not believe the line twist you will get!!! It will look like Charlie Brown and his Kite flying escapade!

I agree with Sinkey, it depends on your rod. If you're worried about snapping a micro guide, go with fluoro. But if your micro guides are have Ti or SiC inserts you should be okay with 10-lb braid and leader, give it a few feet.

Dock fishing: straight flouro (8 to 10 pound)when my casts are short with spinning.

Trees and thick weeds with a spinning rod: 20lb. Sufix 832 braid and either 10 or 8 pound flouro leader. Making long casts over sunken brush with this is good because the floating of the braid keeps it on top of the brush and better chance the bass aint gonna get tangled too much. Straight flouro on a long cast can sink down into it and when you hook up with a bass they have a better chance of getting wrapped up in the brush.

Knots: For spinning (20 braid to 8 or 10 flouro) I mainly use a double albright and for bait casting (30 to 80 braid and 12 to 20 flouro) I use double uni.

+1