There is always some discussion about which one fly a person might use if you were allowed only one fly. I went out today and ran into a day that is kind of unusual for me. After changing flys about 3 times I spent the rest of the day fishing one fly. While I am happy to switch flys based on conditions or structure etc. So when I catch a lot of fish on just one fly up and down the creek I take note. That fly today was a #12 clouser on a tmc200 style hook.
Having said all that what would be y'alls one fly for warmwater (gills, bass, whatever).
Mine would have to be a neutral colored, or black #12 bugger, or that little clouser I used today. HOSS
P.S. I think using one fly would be extremely hard for me to actually do. I am a tinkerer. So if you don't think you could stick with just one feel free to say so.