i like the question.i'll start by saying that who i am engaging with in a given discussion will usually be more of a factor in how the conversation feels (tired vs vital, etc) than the actual topic, although of course the topic will generally determine how interested i am.discussions about leftism, cancel culture/idpol, and any ism around choices people make (identity, food, mind-alteration, etc) get boring for me rather quickly. as do many (though not all, and not all the time) conversations about completely abstract concepts. needless to say, discussions with dogmatists get tired very quickly.
some things i can get very into talking about:
i suspect i will edit this later, but i liked the question enough to want to post a quick answer.