Music is too subjective, with brain formation/environment/nostalgia playing a big part in how a person views a certain song or genre.
Though it is possible to pick apart technically poor songs (auto-tune, lazy rhyming, etc), most people don't realize much of modern pop(ular) music, spanning all genres, uses a very similar chord progression.
Our brains are obviously trained to find the progression pleasing, even if we don't particularly like specific songs that use it.
http://www.youtube.com/watch?v=oOlDewpCfZQ
That being said, the only answer to the perfect song is anything by Air Supply.