"Truly, Madly, Deeply" by Savage Garden. It is syrupy sweet song that I would have never liked, but when I was going through an awful breakup that song was on the radio all the time.
"Ghetto Superstar" or any other gangsta rap without a good beat. It just makes no sense to me and if it doesn't have a good beat, it is very hard to dance to. For example, most of the stuff that Eminem does except "Slim Shady" and a few others.
I like most of the songs others have mentioned, although I do have to agree that Christmas Shoes and Hero are nauseating sticky sweet songs that make my stomach turn.