What is the most effective video game cheat for gaining unlimited lives in a challenging level?

One of the most effective video game cheats for gaining unlimited lives in a challenging level is the "Konami Code." This cheat code, which originated in the 1980s, is a sequence of button inputs that can grant players extra lives or other benefits in many games. To use the Konami Code, typically you would input Up, Up, Down, Down, Left, Right, Left, Right, B, A on your controller. This cheat can help you overcome difficult levels by giving you unlimited lives to keep trying until you succeed.