The thing about Supernatural is that they have a long history of bringing us brilliant characters that we can engage with, empathise with and enjoy. Over the whole 15 years, there have been only a handful of characters that I'm fairy 'meh' about. These are characters that I'm not invested in, I'm not particularly interested in their arc, and I tend to just gloss over them when they're on the screen. These include Asmodeus, Naomi and all the Wayward Sisters teens.
But there is a difference between disinterest and active dislike. And in that long 15 years, there has only been one character that I've actively disliked...
... Amelia Richardson. She's a dull, unpleasant, poorly-written character and she and Sam had absolutely zero chemistry together.
Imagine you're a vet.
A man you've never met before runs into your surgery carrying an injured dog that he's hit with a car. He's frantic and he's gone out of his way to stop his car, get out of the car, pick the dog up, put it in the car and locate a vet surgery. He waits around so that he can check the dog is ok, presumably pays for the treatment (albeit with a fake credit card), and so what do you do?
That's right. you talk to him like he's shit and then guilt trip him into keeping the dog, even though you don't know a thing about his lifestyle and living arrangements.
So Amelia's appearance on the show started badly and went downhill from there.
As Sam's fairly rootless in the time following Dean's disappearance, he hangs around the motel where Amelia's apparently living temporarily, and lo and behold, within weeks they're in a relationship and living together. WHAT????
I don't dislike Amelia because she's the reason that Sam never looked for Dean. She wasn't, she was the distraction that happened while he was trying to get on with his life without looking for Dean. The whole first half of Season 8 was a train wreck, and Amelia was just a contributing factor to the train being derailed.
She was a deeply unlikeable character with no substance and no redeeming features. As she almost always appeared in flashback I was inclined to imagine she was just some hollow grief-fuelled hallucination for Sam, but then eventually we do see her in real time, and that was the time when Sam stood her up at the motel.
When Amelia turned up at the motel and found the room empty I felt not the slightest hint of sympathy for her - just relief that Sam had come to his senses and given her the elbow.
It's important for me to finish off by saying I have nothing against Liane Balaban, the actress that played Amelia. She was just saddled with a horrible, badly written, ill-conceived character in what was, by far, the worst story arc of the show.