2) Pretty much anything from my nephews and nieces, or as I like to call them, my "monkeys." (From the phrase "a monkey's uncle.") It's really nice that they like me enough to want to give me something they hold dear to them, but those things are usually pretty useless. Old toys or things I have no interest in.
Also pretty much anything my grandma has gotten me for Christmas the past several years. Expensive looking Cookie Jars, Snow Villages, etc. They're not exactly useless items themselves, but I never use them and thus far have no intent on doing so. In fact I think they're still boxed up somewhere at my parents' house, since I never bring them home with me after the holidays. Once again, I appreciate the sentiment, but in my opinion the items are a waste of her money and a waste of my (or my parents, as the case may be) space.
3) Two things I can think of, actually:
3.A) I bought a 15-in-1 media card reader and it never worked properly. At least not for SD cards, which are the only things I've tried.
3.B) I also got a retractable USB extension cable, but anything I plug in through it isn't recognized.
I think the real question is: Why do I still have them in my computer parts box?