I don't like the smell of mince when it is first cooking.
However, perhaps "vomit" is a smell I cannot stand.
I'm sure there are some more but cannot think of any, and will probably remember some when I see other answers.
I don't like the smell of poo, but being a nurse there are few smells that I really can't stand. You kind of get used to all the different bodily smells over time and become immune to it all. Hardly notice it after a while.
Yeah Tom Cat urine. And, I can never rest until I find it and even bought a purple light that is meant to magnify it (you have to use it at night). But once you find it, then getting rid of it is a nightmare. Or worse.
Alas I'm a total sook when it comes to bad smells as, unfortunately, I have a very good sense of smell combined with a pathetic, 'paper-mache' stomach! Any toilet smells or vomit and I'm dry-retching before I can stop myself.
Probably one of the main reasons (though there are many) I don't have kids or a dog!
I am like that with Old Spice After Shave. That was very vogue when I was pregnant and every time my husband put it on, we would have to stay home with me stuck in the bathroom with the morning, noon and night sickness.
I can still smell Old Spice 47 years later.