Mine is the Army Men series. Objectively mediocre games at best but the concept of toy soldiers fighting over our yards and rooms has always been cool to me
Oh god the music loops forever and gets stuck in your brain. I haven’t played the 4th game in a couple of years and the score is still regularly stuck in my head.
Their space version of the game, Particle Fleet Emergence, is my most played game in my Steam library.
I wish more people knew about these games!