One word: Mayonnaise! Urk!
Air fresheners, McDonald’s food, oranges. Dear God, I truly loathe the smell of oranges.
As was mentioned, perfume. I don’t mind cologne, but perfume really bothers me. It always seems as though the wearer puts too much on and it’s overpowering. It gives me a tickle in my nose and I get that slight sneezy feeling, but not enough to sneeze. And if I were to sneeze I would taste the perfume.
Also, as was mentioned, air fresheners. The spray kind. They are offensive.
My sister has a thing for magic marker’s. Whenever she sees one she has to smell it.
I don’t like the kind of perfume my boss (principal) wears. It’s kind of weird. Sometimes it smells musky, other times I get the distinct odor of Play-doh.
Coffee, popcorn, seafood, all yuck!
Thank you. I thought I was the only one. Far too sickly sweet for my taste.
The smell of a peeled harboiled egg and egg salad make me gag.
I know this doesn’t apply to anyone now, but when I was in school my classmates liked to sniff fresh ditto pages that were handed out to them. I never understood what they liked about the smell so much, but I hated it.
My sister likes burnt popcorn and its smell-- blechh!
dickcheese
Those little Paperwhite narcissus daffodil flowers they start selling everywhere right around this time of year. To me they smell toxic, but a lot of people think it’s a great smell.
I hate the smell of cut grass. If possible, I hold my breath when I’m near it.
It makes me want to sneeze or puke.
I think these reek too. And almost every year my husband gets some from a student as a Christmas present. Phew.
Oh, so, so many things.
-Perfume. I agree with all the perfume/cologne/aftershave/what-have-you haters in the crowd. It all smells like ass. People walk by me wearing their scent, and I automatically think, “Mmm, badly-run chemical plant in northern New Jersey swampland.”
-Scented candles/incense. This may be some kind of psychological thing, since I was raised Catholic and one time I puked in church just as the priest was coming by with the scensor. Ever since, I associate all burning scented objects with vomit.
-Candy. Dear god, do I loathe the smell of candy, particularly chocolate. I’m one of those strange, unreasonable folk who deeply dislikes chocolate. It tastes like some sort of pre-digested acid-laden waxy muck. Hard candy isn’t as bad, but the weird chemically-flavored smell is upsetting.
-Eggs. Instant barfiness. Cooking eggs permeate the entire house and make me have to stick my head out the window and gulp in the sweet egg-free air.
-Alcohol. Again with the sickness-inducing chemical smell. (I don’t drink either.)
-Flowers. A slight scent of flowers coming from some distance on the wind isn’t too bad, but a room filled with the things is sickening. It’s overpowering, like the smell is taking up actual physical space and crowding me out of the room.
I seem to be particularly affected by chemical odors, yet not those that emanate from actual chemicals. If it’s something like cleaning fluid, which is supposed to have a chemical smell, then it doesn’t bother me. But if it’s something that nominally should not smell like chemicals and yet possesses that insidious chemical under-odor, I feel nauseated and filled with rage.
I also hate the smell of fresh paint, which gives me a headache and makes me feel sick and dizzy, but I doubt there’s too many people out there who like that smell. Same thing with cooking organ meats like liver.
The smell of maple syrup makes me want to hurl.
Flowers: The thickest and most foul smell in the world. All flowers are guilty of this, I can’t recall ever enjoying the odor of any petal covered object my mother has thrust in my face. However, when the scent is dispersed, like in a flower shop, I find the smell to be quite uplifting.
Perfume/Cologne: Mainly because if I’m in a closed space where a lot of people are ‘scented’, or in a perfume store my eyes start burning and my nose blocks up within seconds. Similar to what happens to someone with hay fever if you rub pollen over their face.
Roads/Sidewalks After It’s Rained: It smells like… asphalt. I’ve never found the smell unpleasant, but why so many people enthuse about it has always baffled me.
A lot of people (including myself) like the smell of a burnt-out match. I was wondering if there are people out there who feel the opposite.
Perfume/cologne and baby powder. Pefume that smells like baby powder is the absolute worst.
I hate REALLY smoky incense. To me, it smells like perfumy cigarettes. I also can’t stand fruit scents in things like markers, perfumes and bath products. Floral is fine, but fruit is sickening. . .
Pretty much all fake scents make me feel sick. Perfumes, colognes, scented candles air fresheners (especially air fresheners!) All these things make my me feel naseous.
Flowers at cut grass…I have nasty hay fever so it goes without saying that I can’t stand the scent of either of these items.
Coffee is okay. I hate strong, “bad” coffee, contained in a small area. I don’t mind it in coffee shops, cafes, etc.
I do, however, love the smell of concrete/outdoors after a rainfall. It smells so clean, fresh, and non-allergenic. 
I also like burnt-out match smell.
Definitely Air fresheners. At my office there are 7 stalls in the women’s restroom, and each and every stall has a can of air freshener with a different scent. I have to hold my breath to use the bathroom because it smells so foul in there. Blech. I’d prefer the aroma of a dirty restroom over aerosol-fake-floral-mountain-air-make-me-want-to-vomit smell. Ick, Just ick!
One I haven’t seen mentioned yet: Watermelon.
Definitely hurlworthy.