Ditto to everything Cody said. But I have one to add, and that is to restore versions of the game(s) previously butchered by crackers. I don't mind them cracking, obviously, but when they chop out intros and other game data, or hex edit their names over the people's names who released or worked on the game, that is wrong. ebay has provided me this luxury (of obtaining hard-to-find games).
Games released in the US typically had piss-poor, PC-style packaging with goofy boxes and such, as opposed to the vastly superior packaging from the UK, so I like that part as well. In the old days, I was far less inspired to lay my money down for a gay-looking game box with some retard sitting on a motorcycle in some photo session, when the UK box-art looked like one of the covers of ZZap! and really made you wanna play the game.