I am really interested in people's favorite obscure cards for commander, cards that many people generally don't think of as staples.
As an example one of my favorite black cards is soldevi adnate, feels amazing putting this down turn one or two and by turn 3 you can be doing a 6 drop no problem, and generally people don't want to use a removal for a 2 mana creature, I can't believe how many people I meet who have never heard of it.
Anyway if you have a card like this feel free to share!
Ashes to Ashes is actually pretty popular but since it hasn't been reprinted in a long time, its kind of hard to find. Stonecloaker invertibility ends up in all my decks, it's popular for certain commanders and not so much for others, it's just super versatile when I want grave hate that isn't going to feel like a dead card in some matchups.
I'd like to nominate Telim'Tor's Edict. It's pretty obscure, only in 64 of 137854 decks on edhrec, and it isn't good in most decks, but man is it fun to play in Yasova. Oddly enough, not a single Yasova deck on edhrec has it, and I've never seen any one else play it, but for one mana, you can permanently exile something you've stolen and draw a card. Or if an opponent Briberys something from you, one mana, and it's gone while drawing a card.