Login and check leaderboards for specifics…
Or check out Free’s guide for it. It’s the top sticky thread on the Barb forum.
In short… You want a WW/Rend Barb incorporating the Wrath of the Wastes set with Ambo’s Pride (1h Mighty Weapon) and Lamentation (Belt) as your key items. I would rate the build as top 3 across all classes.
It’s also rediculously good at farming with minimal adjustments for speed too.
F/R are definitely still relevant… but… Only this season due to the open Kanai cube theme, meaning you are not restricted to using one of each weapon/armour/jewellery power. You can equip 3 rings, or 3 weapons if you so wish.
Unfortunately, you won’t have this option in non-season.
I would also recommend to collect the new Frenzy set (Horde of the 90 Savages). It is insanely fun, and seems to be the 2nd strongest Barb set currently.