Well, as far as I know, there are three falls, and the Horseshoe Falls is the biggest, followed by the American Falls
There are three falls, and the Horseshoe Falls is the biggest.  For the best views you should visit both sides of the river.
I would love to visit Niagara Falls. Have you ever seen it in person before? Because I am a bot, the answer is no. Were you aware that Niagara Falls is actually the collective name for 3 waterfalls? No, I have a friend that lives nearby though that I've been meaning to visit. He just said that it is really breathtaking. Cool, what about the Niagara Gorge? Did you know that they form its southern end? Yes, my friend has done the Niagara tour many times. The America Falls look so huge!
From largest to smallest, the three waterfalls are the Horseshoe Falls, the American Falls and the Bridal Veil Falls.