Some things that have worked for me (including some that have been mentioned before):
- Work through them in a loose rotation. Sometimes I'm pleasantly surprised by them, and sometimes I'm reminded why I haven't done them in a while.
- Set aside the videos I'm not sure about in a place I can't see. If several months later I suddenly remember I've done this and realize I haven't missed any of them, I probably won't miss them if they're gone for good.
- Sit down and ask myself why I've kept that video. Does it really have a place in my collection? How do I use it? If I don't use it regularly, why do I keep it around? If I'm holding onto it for more sentimental reasons, do they outweigh the negatives of having them occupy real estate on my shelves?
- Do some research on the video's availability, resale rate / demand level, etc. I rarely get the video's value in return, but especially when I'm eying something new that can be an incentive to move stuff along. Also, if it's readily available (and likely to be even cheaper or more readily available in the future, such as Leslies that are bound to go r/etail to a wider audience), then it's easier for me to let it go.
Good luck!