Right now you can easily do 50-60 damage per swing with a ranger non crit.
My ranger has Colossus Slayer, Light of Creation weapon and Great Weapon Master.
For some reason, GWM triggers on Light of Creations 1d6 Lightning damage and also on the Colossus Slayer 1d8. So you end up with a minimum of 30 damage plus whatever.
If you throw water on someone, the GWM damage on the lightning portion is also treated as lightning, so it does 20 instead of 10.
With some clever routing, you can pick up Light of Creation basically at the start of the game, and it makes for some really hilarious fights where every bottle/barrel of water you pick up is an extinction event for a single enemy.
I don't think anything else currently does that much damage, although I imagine it could probably get beat out by a hasted GWM fighter with the 2d12 minotaur greatclub.
