Mine’s chess, since I used to be really good at it and it’s just complex enough to defy complete analysis (unlike checkers, which has been solved), yet not so complex that analysis is borderline impossible (like in go).

Other board games I like are Monopoly (cunningly trading properties when I know the math and my opponents don’t is still quite satisfying      ) and Mouse Trap (no strategy required, pure nostalgia).

What board game do you like best?