I'm looking for a new storage unit for my CDs. Right now they're scattered over four different shelving units as I just kept buying a new shelf everytime I need more room. I want to buy one (or two if I have to) big shelving units that will store all of my CDs plus have room to grow. Ideally, I'm thinking that storage for 3000 should work for now.

If possible, adjustable shelves so that I can also store DVDs in the same unit would be great.

Does anyone have any suggestions? How do you store your own collection?