For any of you interested in obtaining complete retro rom sets for many retro systems, Underground Gamer is one of the best private torrent trackers to visit. The have a very large user base who all work together on UG projects designed to try and collect together every game for a system.

You can see a complete list of all of their current projects with links to the torrents on the Underground Gamer Wiki here:

If any of you need to join UG but can't register (they only allow registrations when the total members drops below 10,000) then PM me for an invite.