Famous songs people have *heard* a million times but never *listened* to, and when you do, you realise they're amazing (or, a thead about Status Quo).
Everyone knows Status Quo. I bloody love them and listen to them regularly, but they're all too often just cast aside as a near-novelty pub band. You will have heard most of their bigger hits, but have you ever actually *listened* to them? They're an incredible band, incredible musicians, and incredible songwriters.
I can't find the best quality versions of these tracks on youtube, but just sit down and actually *listen* to some of this hits:
Down Down: http://www.youtube.com/watch?v=IdjJydm82_8
Whatever You Want: http://www.youtube.com/watch?v=z7-z4Dz5ZU4
I could go on and on and on. You will think you know these tracks and can probably sing along to the chorus, but listen to the *music*; not the stereotypes or the crap hair or the image or anything like that, but the music. You'll be surprised by just how good it is. Massively, massively ubder-rated, despite being massive.
What other bands/songs get overlooked for just how good they are because of people's pre-conceived ideas?