One of my favorite releases that combined metal, grindcore, and noise was Reek of the Unzen Gas Fume's "Detritivorous Kamigami." Even though they already incorporate some elements of noise into their own material (such as on "Doku"), and had previously released split albums with noise musicians, on the vinyl and cassette versions of this demo the b side consisted of several collaboration tracks with noise musicians (X.E. Reptile Womb, Antichrist Kramer, etc.). Overall, the collaborations were all very good, as well as very different from one another. They showcased the diversity of noise by exploring rhythm, walls of static, and collages of found sounds.
Also, I really like the idea of releasing a demo with collaboration tracks with musicians that you admire. It's one thing to release a split with another band, but actually working together must be quite exciting.