haha, i dont know what my all time favorite is. Ao 2017 is definitely up there ofcourse. To be honest, i'm also lazy so that is part of why i haven't changed my avatar, but i have very fond memories of rg 09 tbh and not just for the tennis , but also collectively going through it with people here, the nadal shock loss, followed by novak promptly losing to all the pressure on roger and then going through that roller coaster match with haas and then del potro, its something I'll never forget and since its roger's only rg, its special in that way.
AO 2017 is special in its own way too and i have many vivid memories. I still watch that 5th set with nerves, even though i know what is going to happen.
After that, i also really enjoyed wimbledon 2012 (funny what many thought to be his swan song) and also someone overlooked, his USO 2008. I feel like that is when the USO audiences really started to pull for him, viewed him as an underdog, and it was really enjoyable watching him show his emotions on court.