Oh God, I'd forgotten just how irritating Ashley/Kaidan are in ME3. Not only did they tell you to take a hike in ME2, but the majority of ME3 is "I don't trust you, Shepard" and "I still don't trust you, Shepard" and then "I want back on the ship, Shepard"..
Get lost.
It's amazing how occupied they were with Cerberus instead of the giant bug eyed things that just paralyzed them and kidnapped half of the colony they were charged with defending.
As for the topic: Excluding the characters we are supposed to dislike (Kai Leng, Linron, Miranda's father, Wreav): Kaidan and Tali were kinda boring in ME1, but hate is probably the wrong word here. The VS was annoying in ME2, Jacob a bit boring with some weird flirt lines and I wasn't a big fan of Thane (creepy flashbacks, and he is a big hypocrite imo). Disliked Joker, Garrus, Samantha and most quarian characters in ME3.