Not sold on Back to the Future-- the game itself isn't bad, and the mechanics are sound... but it was not interesting, and the villian seemed overblown. OTOH it's been years since I watched the movies, so maybe I'm mis-remembering?
Wingspan: Oceania Expansion was pretty solid. Adding a bit more complexity, but less than what the European Expansion added-- so combined, still seems like a manageable game. And the birds added, as well as the artwork, remain beautiful.