For me, the biggest recent let down was Guardians of the Galaxy. The theme would have been a no brainer, but the layout was too much of the same and using sound-alikes for the callouts was rough.
The biggest surprise was Iron Maiden. I had no interest in the theme, but the layout and rules make it amazing. Beatles was also a surprise. I was totally down on it before playing it. . . . .now we own one.