Many years ago my father and I would debate this endlessly. His choice was 40 meters. Mine was 20 meters. After restarting my ham radio hobby 2 years ago, I’ve had a chance to track things carefully this time around, and observe my success on all the bands.
From my recent experience, it appears clear that 20 meters is the “winner”, as it was the first band I completed DXCC on, and WAS on. Other bands were close of course. For the DXer, 15 meters seems to be #2, but for WAS 40 meters is #2.
Neither 20 or 40 is optimal. For 20 meters, the band is small and very popular, leading to lots of QRM but presenting lots of opportunity. For 40 meters, the band is even smaller, filled with broadcast stations and more atmospheric noise. In my mind, there is no doubt that if I could only have one band, it would be 20 meters.
