There are many fantastically funny Amazon reviews. The one for Uranium Ore. The Hutzler 571 Banana Slicer. Brain Pickings had a nice assortment a while back. And here you have some sample reviews for Haribo Sugarless Gummi Bears courtesy of Slightly Viral.
Warning: Don’t read if you find scatological humor offensive! (Personally, I had tears running down my face while reading these.)