My dad was an elementary-school principal for a while, and the annual provincial conference would bring out the fundraising companies, who would hand out samples. Two that I recall were the travel toothbrushes with the refillable toothpaste tube in the handle (the coolest thing ever when I was eight) and the garbage bags in pastel colours. There was no way they would have sold, even as a fundraiser - they were about ten times the price of package of regular garbage bags, and there were only six or eight in a package. They were, however, extra-thick and durable, and we used them for transporting sleeping bags on trips. When you're at camp with a hundred and fifty other kids, all of whom have their sleeping bag stuffed in a garbage bag for protection, having your sleeping bag in a robin's-egg blue bag makes it very easy to pick out in the sea of black and green. Those bags lasted us about fifteen years.
For the most part, our elementary school fundraisers were chocolate-covered almonds, which sold quite well year after year. I recall that one year, my older cousins had catalogs of "candle-holders" - various ceramic tchotchkes of cartoony children doing cute things, with a cup beside them to hold a votive candle. That was never repeated. Aside from the chocolate, I went door-to-door for sponsorships for the heart foundation's skip-a-thon for a few years running. (Jumping rope for three-hours in tag-teams of four.)
I went to a private high school that had an annual work day to raise capital-improvement funds - we'd get sponsors and then spend a day volunteering at different places, usually doing outdoor cleanup. For my grad year, we had a ten-day trip that we were responsible to pay $x for, and there were a variety of fund-raisers to help us do so. (We could have just paid out of pocket if we had wanted, but that wasn't an option for a lot of people.) I did most of my fundraising via the "chicken pull." There were a lot of laying barns in the surrounding area, and the farmers would hire a crew of us to take the old chickens out of the barn so it could be cleaned and new hens brought in. Yes, it was disgusting.
Locally, the most popular fundraiser I see is the sale of gift certificates for local stores, where you purchase them for face value, and the store gives a percentage to the school. The non-school fundraiser (usually for exceptional expenses associated with medical conditions) that I see most often is the benefit supper, where you pay the admission fee and get a meal. The most popular seems to be Mexican food - usually tacos - but I've also seen fish frys and soup and pie suppers.