I'm going to refrain from voting since I still haven't seen Discovery or Picard.
However, I would like to put my unofficial vote in for the Trill as a species. Even before DS9, the very first appearance of the Trill on TNG showed that basically all Trill are bisexual (because it's not the host body that matters when it comes to love, it's what's inside you). It also showed that Dr Crusher was unable to overcome her sexual preferences, and when I first watched that episode, it seemed clear to me that Crusher's inability to see past that surface level was a failing on her part.