I picked up Ironsworn a few months ago and it's quickly become my favorite RPG system. I've played both in traditional GM mode and co-op, and found them both to be great in different ways. Ironsworn keeps the story moving quickly, with plenty of focus on the narrative, while giving you a rules system that feels comprehensive while staying out of your way. The flexibility of the ruleset also makes it rather easy to reskin into whatever setting you prefer -- so don't let the default setting box you in!