I am relatively new to bourbons, but here is my answer...
I think I am overthinking the question, but if I had to only drink one bourbon for the rest of my life I think I would want it to be a higher end bourbon rather than a bargain bourbon. So, I guess my answer is PVW 20. I know that the pricing sucks as compared to the ETL or others, but I would want to go out knowing I went out with one of the best! No regrets!
I tried the Elmer T Lee and the OF Birthday bourbon at the philly whiskey festival and I actually preferred the OF Birthday bourbon. Don't get me wrong, for what we pay for ETL, it's damn good.