Somehow I knew Jun Seros would be a major choice on this forum, though I recently stopped playing the bh story due to the kellian jarro part. As awesome as the bh ship is, and how much I like the mandalorians, there is something you can't deny about the bh story: jun seros was right to about you of murdering jarro (jarro didn't do anything wrong; I prefer antagonists to do something to you so your actions against them are somewhat justified).
As for the villains I hate most:
*Skavak: he's, well, him
*Darth Angral: kills Orgus Din
*the sith emperor: his insane plans, and what happened to Revan and Meetra because of him