Reject the gods with the Oath of Denial paladin!
PDF: https://www.somanyrobots.com/s/Paladin-Oath-of-Denial.pdf
GMBinder: https://www.gmbinder.com/share/-OogU9bkdKbfhPgmeUN1
This was last month's general poll winner — one I've polled before that, interestingly, never did very well until now. (That happens sometimes! One reason I rarely put an idea to rest for good). The idea here is a paladin who rejects the gods and is devoted to fighting what they see as the corrupting influence of faith.
Thematically that's a pretty strong idea; mechanically it's tough to do a lot with. The obvious trap would be an "anti-divine" subclass, but that would be so narrow as to be virtually unplayable. There's room for a cool against-the-gods campaign where you're fighting priests, paladins, and celestials; but it's not like people are playing that campaign all the time. So mechanically the subclass broadens out a bit to more of a general anti-mage feel.
Your Spell List is a little short and has an imperious feel to it, with command, silence, counterspell, compulsion, and dispel evil and good. The short spell list is compensated for by the next feature, the first Channel Divinity Empowering Oath. This lets you steal spells. Only one per level at a time (effectively filling out your oath spells), and you take a little damage if you cast cleric spells. This is quietly our biggest feature, and can probably let you do some really gnarly things on a paladin chassis; but being a half-caster limits the blast radius for broken interactions. Your second Channel is Disrupting Smite, which lets you do a psychic smite and buffs your next attack and spell against the target. Also, for our anti-mage theme, it's great at breaking concentration. Aura of Denial kicks in at 7th for a standard paladin aura, in this case granting advantage against charm spells and auto-success against illusions. Unbreakable Will is a pretty standard defensive feature at 15, two resistances and a legendary resistance on mental saves. And the capstone at 20 is Avatar of Faithlessness. A little unique in that this mixes in a little utility on an otherwise combat-focused feature, it gives you free zone of truth, free illusion countering, and free Disrupting Smites.
As always, you're invited to come discuss and offer feedback in the comments or on Discord!