Inspired in an NFL thread when someone, I don't know if it was a network montage or the team itself, used Green Day's "Time of Your Life" as a sendoff for the recently departed Wellington Mara... except the fact that, if you pay attention to the song, it's a horrible song to use as a sendoff/funeral song, yet I've seen it used for that purpose many times since its release
Other examples:
Using "Every Breath You Take", a song about a stalker, as a wedding song
Using "Born in the USA", a song deriding the US gov't, as a patriotic song
What else can you think of?