It was hard to select a winner. All the entries had their own appeal. There were certainly no bad lists (well, maybe one). But there can only be one winner.
(Picture of Ares/Gabrielle fun time found during image search of "guilty pleasures")
After running each mixtape through the Ghostmatic Analyzer 2000 I concluded the winner is Corpsegoddess.
Her mixtape is titled "Songs That People Have Said I Should Feel Guilty About Liking But I Only Feel Awesome KTHXBAI" since she has no shame in her game (which makes her a better person than me).
The Proclaimers - I'm Gonna Be (500 Miles) 3:37 (link edited to play in US)