For me it is the cooking odor of eggs or ANY cruciferous vegetable. DH can cook eggs if I'm not home and he cleans up before I get home, but no cruciferous veggies ever enter my house; I hate the smell that much.Limburger and other stinky cheese.
I don't mind the aroma of cauliflower and other cruciferous vegetables cooking. I suppose I'm used to it.
Supposedly the worst smelling fruit is a durian, popular in some Asian countries.