Can owners who legally purchased DVDs, CDs, and video games resell the said items?

Original versions can be resold, copies cannot. The "first sale doctrine" rules here - once the copyright owner has made a first sale and been paid for it - no more money can be collected by the copyright owner. Used books, CDs, DVDs, all can continue to be sold by future owners. Pending TPP and Fast Track bills should not change that - but we need to monitor them - just in case.

You can legally sell almost anything you own, including digital materials. However, you can't purchase and import massive numbers of any particular work without a distributor arrangement with the copyright owner.