I wasn't much of a Cars fan when their first album came out. Good Times Roll and Just What I Needed were the songs. My first thought was that they were too simplified - it sounded like something I could play with little musical experience. My opinion changed within a few months though and I ended up getting, and enjoying, the first album.
There's a couple of artists that I disliked for a while because of their voices. I eventually got over that and now can enjoy most of their music. That was Joe Walsh and Neil Young. I'm still working on Dylan.
I think there's been many, many songs that I disliked at the time, for one reason or another. I hear them now and I mostly enjoy them. Usually. Midnight at the Oasis - Maria Muldar. Rikki Don't Lose That Number - Steely Dan (Don't know why I didn't like it (<might have been the cryptic lyrics> but I love it now). The Logical Song - Supertramp. (I probably enjoy it now for the sonics moreso than the performance... but I do enjoy it). Leo Sayer - You Make Me Feel Like Dancing (this got A LOT of radio play and it's still not a fav but I can tolerate it now, probably because of nostalgia).