I've been to Niagara Falls more times than I can count, and it is ALWAYS simply incredible. I've stood by the falls for hours, until soaked by the spray. I've also been there when the smaller section (The American falls) was frozen.
Water plunges more than feet over the edge of the Auyantepui mountain in Canaima National Park, Venezuela. With a total height of more than feet, Kerepakupai Vená, also known as Angel Falls, is the highest uninterrupted waterfall in the world.