Over at www.livemetallica.com you can download Metallica's 1985 Donington Monsters Of Rock set free of charge. It's free to sign up at the site and there's a good selection of free downloads from 1982-2003. Here's the full list of freebies:
10/18/1982 Old Waldorf, San Francisco, CA
12/18/1983 Agora Ballroom, Cleveland, OH
12/20/1984 Lyceum, London, UK
3/15/1985 Kabuki Theater, San Francisco, CA
8/17/1985 Donington Park, Donington, UK
5/24/1986 Arena Building, Cape Girardeau, MO
7/29/1986 UTC Arena, Chattanooga, TN
9/21/1986 Hammersmith Odeon, London, UK
2/13/1987 Frolundaborg, Gothenburg, SWE
2/3/1989 Erwin Events Center, Austin, TX
7/18/1992 Giants Stadium, East Rutherford, NJ
6/17/1994 County Fairgrounds, Middletown, NY
8/23/1995 London Astoria II, London, UK
10/6/1996 NEC, Birmingham, UK
12/21/1996 Great Western Forum, Los Angeles, CA
7/8/1998 Blossom Music Center, Cuyahoga Falls, OH
7/19/1998 Great Woods Center, Mansfield, MA
5/21/1999 Frankenstadion, Nurnberg, GER
7/13/2003 Citrus Bowl, Orlando, FL
Additionally, you can buy many shows from recent tours - sadly the band's Reading Festival appearances are absent, but their Donington 2006 show IS available.