Hands down the best sac outlet in the game, Viscera SeerViscera Seer would be excellent if it was just a one-mana creature that said "sacrifice a creature" on it, as evidenced by Carrion FeederCarrion Feeder
Also, imagine trying to attack an opponent with six mana up, a bunch of cards in hand, and three payoffs in playitd like be paralyzing, and your opponent could just keep making land drops while building up an even better defense you cant see
For this list, Im considering permanents with activated abilities or triggered abilities that allow you to sacrifice creatures or permanents as well as cards that require a sacrifice as an additional cost
Five-mana spells are expensive in modern Magic, but warp makes this wonderfully flexible since its a reasonable play on turn 2
Swan Song If youre not smitten by either of the first two cards, then let me pique your interest once more
This is a completely self-contained engine, creating, sacrificing and pumping tokens at your leisure