FYI, the Champion Fighter 20/Devotion Paladin 20 I mentioned above assuming 20 Str and Charisma, would do a reliable 10d8+35 DPR with +16 to hit. You'd have a 15% chance of critting which would double that.
If you spent a single spell slot smite each attack, it would be 20d8+35
If you spent your 5 biggest spell slots to smite, it would be 35d8+35
If you spent your 5 biggest spell slots to smite, AND used your action surge, you would do a ridiculous 65d8+70 damage in a nova round.
All that is assuming dueling fighting style with 1d8 weapon with no feats or magic weapon. If you stepped up to a greataxe and took GWM and GWF, you'd still have +11 to hit and still have 15% chance of critting.
A regular round would be 5d12+5d8+75. Your nova round would be 10d12+55d8+150 after action surge. Of course assuming you hit everytime but not accounting for potential crits which would add 1d12+6d8 each time.
Of course just to be silly, if you were a Half-Orc and crit every time, you could do a theoretical 30d12+110d8+150 in one round