If you like math puzzles, Meganum is something that I've been playing for a long while now. You have a grid of numbers where you need to make them all work in a way to result in the proper sums for all rows and columns.

Quadline is a great puzzle game where rotate pieces around a board with different movement types to get things into their correct place.

My favorite is Hoplite which I've been playing for over a decade at this point. It's a combaty turn based strategy where the goal is to descend downward and retrieve the golden fleece.