Hmm, surprisnigly enough I didn't really collect much of anything from my childhood. I still have a bunch of Sonic Comics that I used to get, but that wasn't for collection purposes so much as just reading them for enjoyment. I still have Issue 0 of the original limited series run though. It's probably not in great condition or worth much though since it was bought to read and enjoy not for collection purposes.
I guess my game collection is pretty good, I don't have anything hugely rare, but I have some cool stuff;
* Dreamcast Wristwatch
http://cache.gawkerassets.com/assets/im ... twatch.jpg* House of the Dead Overkill VHS styled Press-kit
* Shining Force III Trilogy JP Discs (Will get the premium disc eventually as well)
* Panzer Dragoon Saga PAL (with the cardboard over-case)
* Marvel vs Capcom 2 Xbox (Surprisingly this is actually rare, since the licence ran out as they were producing it, meaning they had to cut their print run short)