What is best to use for river largemouth bass fishing? Monofilament, fluorocarbon, or braided? What pound test?

Big Game Mono 

Depends what lures you plan on fishing? What type of river are we talking? The answer could range from 6lb fluorocarbon if you are fishing for smallies in the st Lawrence or 80lb braid fishing thick lily pads in an oxbow somewhere. 

That's a very broad question that is going to vary a lot depending on technique, and cover/structure you're going to be fishing. 

As Blubasser86 stated, many of us use different lines for specific techniques.

If you are more interested in "all-around" line I would suggest #6 monofilament

for spinning tackle and #12 mono for baitcasting.

 

This is how I roll:

Spinning: #4 Yo-Zuri Hybrid

Jigs and weighted soft plastics:  Tatsu #15 or #40 Smackdown with Tatsu leader

Treble hooks:  Sunline Shooter Defier Armilo #11

 

BERKLEY TRILENE BIG GAME !

 

Nuff said !

I like Berkley Trilene XT 8lb on spinning gear and 12lb on Baitcasters.

 

I also use Kastking Superpower braid 30lb and Kastking Fluorokote 8-12lb depending on the lures I am fishing or cover I am fishing in. 

 

Those 3 lines are what I use the most when river fishing

Not knowing more details I would recomend Suffix 832 20ib if I could only go with one line. Use it as is for topwater or add different floro leader for most everyting else. The lb test of the leader can be changed based on what you are fishing with.

15 hours ago, soflabasser said:

Big Game Mono 

this x2

I'm with @Bluebasser86 and @roadwarrior, very broad

question.

 

My setups are all braid + leader.

 

Spinning:

Power Pro (regular) in yellow: 10# test

Power Pro Super Slick 8 in yellow 15# test

 

Casting:

Power Pro (regular) in yellow: 20# test.

 

Leaders:

Yo-Zuri Hybrid from 4-15# test

 

Gamma Edge Fluoro in 6, 8, 10# tests

Have been using braid + flouro leader for most of this year.  I have been slowly switching what few rigs I have to braid.  I currently am liking it better than flouro for a few reasons.