My first system was a ColecoVision, but Master System is really the first system I have vivid memories of from childhood. I think the Master System overall was my favorite part of being 4-6 years old - playing Shooting Gallery, Fantasy Zone, Ys, Missile Defense 3D (I think that was the name), etc., It also felt mysterious (?) to me because a.) I was the only kid I knew with one and b.) things like the hidden game (I forget the game exactly) that would come on if turned on the system with no cartridge inside.