Love the question, because I am moving my craft room from one room to another in a couple of months, and I really want to have a clear out. I hear you about buying oodles of stuff when you first start out- I have hundreds of decoupage sheets bought when I first started cardmaking, years ago. Now I couldn't tell you when I last made a decoupage picture. Like you I have loads of 'what the hell was I thinking' paper, and that is definitely getting sorted through. Most of it is so awful/dated that I don't even think I could pass it on to anyone I know. Out of embarrassment as much as anything else.
I've kept magazines & mag articles in binders for 'inspiration'. Again, dont know when I last looked at them. I went through the eyelet setter phase too- tried them all, finally settled on the Silent Setter for obvious reasons. The others are still in drawers somewhere.Every time I have a tidy, I find stuff I'd either forgotten about, or don't even remember buying- how terrible is that? I shall be interested to see what others would cull- I do know my stamps, inks & die cutting stuff is safe. I've got folders full of 'freebie' papers etc from magazines- I really have to force myself to use them. I think thats the trouble, stuff gets filed away, and its out of sight, out of mind. And our directions change, now for me its all about stamping, so thats what I'm keeping.