Namely my own.
A while back I was browsing around one afternoon in the fabric store. I was in the notions aisle to get snaps or something, and I turned around and saw the following item, which I proceeded to buy. This item has been the stupidest craft purchase I have ever made:
The Seam Ripper of Stupid. Now a seam ripper isn't altogether a stupid item. It's a very useful item which I encourage all sewing crafters to have. THIS PARTICULAR seam ripper, however, is the stupidest seam ripper on the face of the planet.
It's downfall? It's not sharp. That little U down there at the bottom of the point? The place where all other seam rippers are sharp to cut thread? It's not. It's like the safety scissor of the seam ripper family. Ugh. Way to go, Ubiquitous Sewing Notion Company.
I didn't even need this particular seam ripper. I have a perfectly good (albeit small) one that I got in some sewing kit or something and it's served me well for quite a while. But I turned around and saw "ooh pink!" (which was probably their whole purpose of making it that color) and decided I needed a new one with a cushy handle. Stupid.
What will I do with it? Who knows. I may keep it around for poking things/people. But it's sure no good for doing the one thing I DID buy it for...