I know one round damage isn't the only measure of class power, but it is fun to measure, which classes do you think can beat it easily?
I'd also be very interested hear about those other classes that can bring the pain.
Consistently?
Crossbow Expert/Sharpshooter Fighter (EK). You can do a few levels ranger to get Hunter's Mark.
Sorlock. Sorcerer/warlock using Quicken Spell to fire double eldritch blast for quite a few rounds.
Paladin. GWF Vengeance or Oath. Use your Channel Divinity to eliminate penalty for GWF. Hammer with smites.
Rogue (AT) with haste. Use your haste action to ready an attack on someone else's turn. Generally allows for 20d6 attacks per round. You can also take Crossbow Expert for an extra attack with Crossbow.
Most of these combinations will allow you to do more damage consistently. The paladin's nova can be quite impressive. You can do this more often than most caster classes. It's usually easier to do than dragging around skeleton armies.