"hi, I hope you're well."
"hi, what's up?"
These introductions clearly tend to trigger me as I interpret them as someone who wants to ask for something but isn't brave enough to simply ask for it so she/he keeps walking around you desperately looking for a sign of welcome.
When this happens, I usually just reply with:
"Hi."
Then I pull out my popcorn and watch the "X is typing a reply" prompt come up then disappear, repeatedly for the next minute or two.