Megadeth and Anthrax Signed Revolver "The Big Four" Magazine. 

This is the June/July issue of Revolver Magazine's special "Big Four" issue. Magazine came out before the Big Four's Indio, CA show in 2011 and was personally signed by both bands in full:

Megadeth: Dave Mustaine, David Ellefson, Shawn Drover and Chris Broderick

Anthrax: Joey Belladonna, Scott Ian, Charlie Benante, Frank Bello and Rob Caggiano

Both bands signed this at the Revolver Golden God Awards the night before the first Big Four show in 2011.

The signatures are pristine and this is guaranteed to pass any 3rd party authentication (JSA, PSA, etc...) this is a must have for any fan of these three bands.