Some great recent mashups are Ariana Grande x Ciara - Problem Yeah I Know (Mashup) (Feat Iggy Azalea) and Bang Bang vs. Shake It Off (Mashup) - Jessie J, Ariana Grande, Nicki Minaj & Taylor Swift.
There's also the great Iggy Azalea ft. Charli XCX vs. Britney Spears - "Fancy One More Time" (Mashup).
The Interstellar score by Hans Zimmer is also excellent, but be sure to hear it first with the incredible images of hurtling through space in the film--try 'Day one dark' for a sense of the haunting, atmospheric terror. It's almost like an intellectual, complex, esoteric, humanity/Carl Jung-focused version of Silent Hill. Many people have enjoyed the great song featured in the Exodus film trailer, Sydney Wayser's 'Belfast Child', it's quite moving.