The photoelectric effect was at the heart of not just one Nobel Prize, but two! If you can plunk down $175 for a short wave UV source, (or borrow the one your biology teachers might have around for looking at bacteria) you can visit the grocery store to get everything else you need to demonstrate the photoelectric effect.
I'll also tout the soda can electroscope, which, for the low-low cost of dumpster diving, is superior to commercial electroscopes as far as I'm concerned. The pie-plate electrophorus is also as good or better than any commercial one on the market. Just imagine what Ben Franklin might have discovered with access to the wonders of modern take-out containers. As it was, he had to do with pewter and wax -- it was definitely a different time.