I'm keeping up with IMSA and WEC. I'm also watching all the major GT endurance races (e.g. Bathurst 12h, 24h Spa, 24h Nurburgring, Silverstone) outside of them.
I've been casually watching GTWC (mostly EU and America), ELMS, ICGT, NLS, and DTM. I occasionally watch British GT, GTWC gt4, dark horse challenge, Porsche cup, super trofeo, and various touring car series. I haven't been keeping up with Creventic 24h series this year. I gave up on Aussie Supercars when my source dried up, and there's so much free content on others I don't bother (it is a great show though, and I always try to find a source for the Bathurst 1000).
That reminds me, I'm behind after being out of town last week...