these will probably be more subjective answers even than usual.
topics that are still fascinating but that now i have to be convinced to participate in (by the specific context): sexwork, violence, individual vs group, identity, power
i mix things up (when i can), by having the conversations with people who i trust will allow me some shortcuts (in jargon, for example)--so that we don't have to re-walk all the well-worn paths--and/or by re-framing the conversation, partly so that it avoids trigger words that tend to shortcircuit people's brains. although sometimes it's the use of those words that makes people interested enough in the conversation to even have it... ("why do you want to talk to me about philosophical definitions of 'power' when we could be talking about fascism..." etc).