well that's a tough question which can't be answered. I basicly love all their songs. But maybe i can tell you which one i don't like. That list is shorter than the other one.
In my opinion Party Girl is thei weakest song ever. :( Hurts to say that, but i was never a huge fan of this song and after hearing the other songs from the album, this was deffo the one i didn't like that much! :)