I'm living for Bruce and Barry's friendship being grounded in their interest of forensics, both neatly organizing their files and evidences, and studying crime scenes meticulously. You make Flash and Batman stand next to each other, you wouldn't think they share much, but actually, they both are animated by the murders of their mothers in front of them, cases they had to investigate themselves from a young age. They discuss and solve cold cases during break at the Watchtower, so happy to see each other so they can rant about that case they worked on to someone that understand wtf they are talking about.