Book threads, in particular, the 50 book challenge, well I would, I started it 
Then all manner of random stuff, it could be anything if I feel I have something to contribute, what's in the news and then in no particular order, food, travel, the arts, culture, children, grandchildren, animals history, genealogy, the natural world. all are of interest. I steer clear of crafts or sewing definitely not my forte!.
I sometimes read through the comforting threads. Good Morning/Soops Kitchen. The contributors come across as mutually supportive and often give an interesting snapshot of their individual part of the world. Just good to know they're there.