This one's easy, because I have an official character playlist (that's a Spotify link) and word-of-god that "Blood in the Cut" by K. Flay (NB: definitely NSFW lyrics, but here's the lyric video, now that I'm back at a keyboard) is the quintessential Beauregard song, and I absolutely concur. Without all the heterosexual stuff, anyway.

That said I'd love to see what other people think!

ETA: You know what, let me just link Marisha's commentary on the playlist because WHY SHOULD I BE THE ONLY ONE PUNCHED IN THE FACE BY FEELINGS.