Fantasy Flight Games' narrative dice system / Edge of the Empire.
Which is not to say that I didn't have at least some expectation that it would work when I tried it, but the two sessions we got in before the pandemic broke up our group in March 2020 were excellent. I was expecting it to be fun, but was also expecting a lot more choppiness, slowdown, and overall "kludginess" than we experienced.
So overall it very much exceeded my expectations. Once we finish our Tiny D6 / Tiny Frontiers experiment for the next 4-6 weeks, I'm fully expecting to go back to it.