Then there's this:
http://www.youtube.com/watch?v=9k7DrIWcrdI
In which Konami opted to remove the MGS theme from MGS4. Yeah, way too similar. Sorry TAPPY, but you're busted. Melodies and chord progressions are WAY too similar to be coincidence.
Also for the handful of people familiar with the music of Timesplitters 2, the level "Notre Dame" uses excerpts from Mozart's "Requiem" as well as Bach's "Tocatta and Fugue in D Minor". I doubt these were plagiarisms though and rather homages to the originals.