Nope, it's no good... I've tried going through my collection, and there is no one song - let alone 5 - that I could point to and say "This is the best song of all time - I mean, it's got everything: passion, craft, awe-inspiring and intelligent lyrics, a catchy melody, beautiful harmonies, wit, endless replayability, individual musicianship of the highest order, etc".
Every song I possess has some of the above qualities - some songs more than others - but no one song could stand objective scrutiny when my reasons are so nebulous and subjective.
I mean, take the song I'm listening to at the moment: Joy Division's "Transmission". Songwriting craft? Nope. Nothing clever about it, it's quite repetitive, in fact. Intelligent lyrics? I think not. Musicianship? Don't make me laugh. And yet I can listen to it again and again, thanks to Ian Curtis' haunting melancholic vocals, driving Hooky bass, and - perhaps most important of all - the memories that it triggers.
Probably the longest "Don't know" answer in recent history...