Well, it depends on where the bake sale is. Mostly kids or adults? I usually can't resist a rice krispie treat, though!
Things that "go" are clearly labeled what they are and if they do or don't contain nuts.Also things that are packaged nicely. I also see a lot of mini loaves of bread (banana, zuchinni or something else) go at my church.
Brownies are always popular here, swirled if possible. Cookies too, but I prefer brownies, one bowl, one pan, one trip to the oven. nice & easy.