I have a metric ton of old D20/D&D 3rd edition stuff. It's all good stuff that was really useful at the time, but I have moved on and its now being neglected.
All the basics, couple of splat books and 3rd party supplements
Just about all of the nice Scarred Lands setting, produced by White Wolf.
A few stand alone D20 supplements, like Dragon Lords of Melnibone and Slaine, Traveller, and Stargate (just the basic book).
There's a LOT. And it needs to go.