I've used Green Disk several times, mostly for recycling/repurposing computer disks. I found them reliable, if costly. However, it was the only company i could find that would certifiably destroy the data as well as recycle the result (to the degree possible).
I did not use Green Disk for audio or video tapes, as all of mine were commercial (no personal information means no security risk) and shipping video tapes would be expensive. They, unfortunately, went into the trash (landfill). There were no other solutions in my area (Midwest).