I can’t think of anything worse than: “I’m so stupid to have believed in you.” I don’t think I’ve ever merited that remark, but I feel dread at the thought that I ever might do so.
“I don’t love you anymore”.
Hurts like hell, let me tell ya.
From a SO it’s really bad but if I ever did anything to make one of my kids say this…
let’s just say I pray I never become the kind of person who would do something to make my kids say that.
“I have a gun pointing at your heart” would have to be up there.
“I never loved you; it was all play-acting” is much worse.
“I never loved you; it was all play-acting so that I could get to your bank account, which as you’ll notice shortly, has been cleaned out. Oh, and I just fed your cat poison.”
“…also, there is no Santa Claus.”
Another vote for “I never loved you. I was just using you the whole time.”
I switched lotto tickets with you 
"Your client was so stupid to believe in you. *
It’s one thing to fail a friend personally - quite another to fail someone who faces ruin should you not be up to your job.
"You’ve never really lived, Doug. You don’t know life. You never paid your dues in life. You haven’t earned your humanity – in fact, I don’t even think you are human.
"You might have a chance – if you opened up and learned to take the pain we others bring, and the joy that goes along with it. But you won’t. You’re too lost in the misery you’ve brought on yourself. We could never take that away – and now you can’t either. Not without taking on our misery along with your own.
"That’s right, Doug. As low and worthless as you feel, you’re going to have to go even lower. You’ll have to give up what little peace and happiness you’ve ever known. And then you’ll have to earn every little bit of it you’ll ever get again. You’ll have to be nothing more – or less – than a slave to life. Only in that bond will you ever be free again.
“Resolve yourself to that and you have a chance – no promises, no guarantees – at being human like the rest of us.”
“I wish you were not my child” has to rank pretty high.
Child: “Is there any time, ever in my life, that you loved me, even a little?”
Stepmother: “Could you love a pebble in your shoe?”
-Ever After, Drew Barrymore and Angelica Huston
Having my lovely little mood disorder means I tend to feel things, both positive and negative, with intensity.
My first biggie was “You cant play football anymore”. It meant retirement in my early 20s. It was a career I had trained for my whole life, up to that point.
I went back to school for culinary arts/f&b management, which was the only other thing I really loved to do. I was very successfull too, but felt deflated when a friend told me that I had wasted a really great mind on a trivial occupation. If she wasnt female I could have smacked her.
Doug, can you elaborate on this a little? It sounds like a horrible human being said this, but you seem to give some weight to it.
“Every day I’ve spent living with you has been a day I’ve spent dreaming of a way to escape this awful nightmare.”
And no, that hasn’t actually been said to me.
On a lighter (and yet, more realistic to me, note): “Turns out that, once I went black, I could go back.”
ETA: I think it’s appropriate to add the worst thing that someone actually has said to me, which was: “I didn’t think you’d care [that I’d already gone back to seeing the guy I cheated on you with before you had a chance to move out of the house] because you felt like you’d already lost.”
“We only adopted you because it was our duty, to hide the shame in our family.”
And yes, that has been said to my face.
I am that horrible human being. I’ve told myself this. It’s just a part of the bad trip I’ve run on myself over the years as a depressive individual.
“Mrs. Carter, this storage facility your husband rented is completely full and unless you come empty it we will be throwing away the contents…”
I’ve been dealing for the past year with getting rid of the detritus of a packrat’s life. Gah. If this happened, I’d just go hide in a corner.
On a similar note, the most painful thing ever said to me was along the lines of “You never loved me.” Not only does it carry all the sting of the idea that the love was never real, but it’s straight out denial of how I’d felt and the things I’d poured my heart into to express that. I’d rather hear that “I never loved you” bit because at least I’d know I was still genuine.
Of course, I came to realize it was something that was said deliberately knowing how much it would hurt me, after all, who knows how to cut you the deepest but those whom you love the most? But, damn, it still sucks thinking about it.
Said by my brother’s ex to him, while breaking up: “I’ve decided I want children - but not with you”.