You can't beat the box tops for education labels. We do this every year as a contest per classroom, each month the "top collecting" classroom gets something (box top pencils, etc) and the top overall classroom at the end of the year is rewarded with a box top party (things that have the box top label on them)
It is the easiest fundraiser out there in my opinion. We have a volunteer per grade level cut and bundle them and an overall coordinator over sees it and sends them in when needed.
It isnt a fast money maker, it is a school year long thing, but it makes a great addition to the other things you are doing. All you are doing is asking parent to send in the labels off of the products they are already using. At 10 cents each, it really does add up!

For the most money with the least amount of work, I suggest any brochure sale. We are doing Sally Foster again this year. After researching others, the Sally rep gave us the highest profit and an up front "bonus". Profit and incentives are negotiable. Make the sale "your own" by offering non-cost incentives such as no homework for top class, lunch with principal for top seller each grade, reach a goal, principal does something silly (ours sang from the roof). Don't forget the teachers too. Offer them an incentive of highest participation level gets you dinner at a great restaurant. This year we're contemplating a "mega" party for reaching our goal. We will bring in inflatables and carnival games for an afternoon party. Everyone hates these brochure-type sales, but you can't deny the easy money your organization will make.

This is my first year on the pto board and I have been elected to help with fundraising. Please any suggestions on the best programs and the most profitable ones please let me know. Thanks..