What's the least demanding PC game ever? any genre, not emulated(non-FPS/CPU intense)

I saw a thread asking what the most FPS demanding game of all time is currently, and I'd like to know the opposite; WHAT IN TARNATION is the easiest official PC game to run? Meaning the least demanding in terms of all hardware parts (leastgpu,cpu,ram usage)? I'm hoping to get some answers I don't expect. There's some obvious contenders but I haven't seen benchmarks for this so my curiosity is peaked for the truth.