Following up on the worst projects, how about tools, accessories or whatevers that you found to be almost useless?
I'll start
Clover mini iron - words can't express what a waste of money that was
Cord makers -- All my stitching buddies had one so I bought a battery powered one that worked great for a while. When it died, I bought a manual one that I hated so I bought another battery powered one that I've used maybe 3 times