The wheel would have to be a strong contender for the greatest gadget of all time. It's deceptively simple yet revolutionized human civilization, enabling everything from transportation to machinery to pottery. Its impact has been so profound that we're still finding new applications for it thousands of years later.

However, I could also make a compelling case for the transistor. This tiny electronic component fundamentally transformed our world by making modern computing possible. Without it, we wouldn't have smartphones, computers, or any of the digital technology we rely on today.