I've been on a big DCAU kick lately, which just started off as "oh hey I can watch Justice League, now I can see the second part of that episode I never saw the second part of"
The episode was the one where they go to an alternate dimension, and meet superheroes of times long past, and it turns out I did see the second part of it lmao, but yea I watched all of that and then Justice League Unlimited. Now I am midway through Superman The Animated Series, and then I may take a break, followed by Batman The Animated Series. I think that's all the DCAU?
At some point after this I want to re-watch Harley Quinn, because it's been a while and also I only saw season 1 and 2, and I think they've got four of them now