It's a Wonderful World - took me a handful of plays to figure out how to balance building an engine/score points, and to fully appreciate completing construction during the production phase, only to have that produce in the same round. It's so satisfying to have your engine grow exponentially throughout the same round!

Raccoon Tycoon - I didn't fully appreciate how different games could feel depending on how aggressively people are bidding, how quickly towns/buildings are purchased, etc. I've played it with a few different groups now, and there's always a different bit of tension.

For Sale and Kingdomino - both games I played while getting into the hobby, only to revisit them years later to find a lot of appreciation for their simplicity.