M.C.
My boys were both in cross country all 4 years of high school. The best fundraisers they did were selling candy, donuts, and doing car washes. They had some horrible ones, like selling idiotic coupon books, $20 cheesecakes of all things, and $18 tubs of flavorless cookie dough. The candy and donuts sold well because you could sell them anywhere and they were cheap enough that people would fork over a few bucks. Who is going to buy $20 cheesecakes???
The car wash worked well because they could go to a busy location and everyone and their brother could drive by and tons of people would stop in.