Gonna have to give my #1 vote to CRP2 July 2019.
Not only was it nostalgic to see many familiar names I hadn't arrested in over 5 years but it introduced many great new gameplay mechanics. The resource economy/company system worked well, even if for just a short time. The map was one of the biggest CRP maps I believe, and really fun to traverse. I absolutely loved the perk system and wish it were completed. My only real downsides to this version were the lack of hunger and the relatively low playercounts compared to previous servers.
A close second would be Furdle Aug 2012. This one had the overall best map imo and a really fun and chaotic selection of players from what I remember. Those two factors are what makes CRP to me. The downside to this one is in the name itself.