I had that problem too. I inherited a PAPER CASE box full of knitting needles, which was a HUGE mess.
I finally bought an over the door shoe bag and hung it on the ack of my bedroom door. I labeled each pocket (using a Metallic silver Sharpie since the shoe bag itself was black) with needle sizes and sorted the straight needles into those pockets, 1 size per pocket until I got to the LARGE needles which are all in one pocket (17, 19, and 50). I also made a Single pocket for the few DPNs I have, and rubberbanded a lable to each set before putting them in the pocket. Then I grouped the circular needles into 5 main size groups and sorted them into 4 pockets, labled circular size 1-2, 3-4, 5-8, 9-11, and 15 and larger. I also labled a few pockets for stitch holders, crochet hooks, and accessories. Finally, I dedicated the top drawer of my 4 drawer cabinet to my interchangable sets (I have 2 different brands of interchangables) and hairpin lace looms.
I still have to check sizes and cord length when I want a fixed Circular, but at least I do not have to look at ALL of them, and everything is contained, neat, and out of sight.