1. Vex, who will still talk down to you even after you are the Guildmaster.
2. Astrid, I just don't buy the whole "sexy assassin" bit.
3. Aela, who was a bitch to me from the beginning.
4. The Imperial Captain who ordered my death, even though I was only convicted of a minor crime.
5. Serana, who is just a complete annoyance in my opinion.
6. Maven, although I do find her interesting, I don't like the fact that she is basically untouchable regardless of any storyline.
7. Maul and Dirge, it's not hard to tell they're brothers, they're both hardnosed pricks.
8. Irileth, because she has some sort of obsession with protecting Balgruuf.
9 Honorable Mention: Farkas, Just had to mention Farkas. I actually like Farkas, but during my first real playthrough I acquired a bounty in a hold that was unknown to me, and Farkas attacked me in the snow. I beat him and his two companions, but they chased me and I had to fight them again and run. When I finally joined the Companions, Farkas wouldn't leave me alone. Every two seconds I would be walking around trying to finish the Companions starter quest, and he would keep initiating conversations with me. I was infuriated. Imagine, every two steps: "Everything alright?" "I'm here to help." "Be seein' ya." "What do you need?" I finally found out that all I had to do was pay off my bounty and the big lunk would stop following me around, so after I paid up, we were old friends again.