Carcassonne

This game is amazing: https://boardgamegeek.com/boardgame/822/carcassonne

But it is surprisingly simple how to play. On your move you place a tile where it can fit and optionally place a meple on that tile. But there is a lot of decisions such as where you place the tile and with what rotation. Then deciding where do you place the meple that is if you decide to place one this turn.

There are a dozen-plus expansions. I own several of the expansions.