Haven't read through the whole thread, but yeah, I can't stress this part enough. I live about an hour and a half from Niagara Falls. Highly, highly recommend the Canadian side if you can manage it. I've done the Maid of the Mist (which was an amazing experience) as well as the thing where you walk behind the falls (can't remember what it was called, but also very cool).
If you make it to the Canadian side, also highly recommend Antica Pizzeria. It was featured on the Canadian version of Food Network; award winning thin-crust wood-grilled pizzas. Amazing food there.
And if you have extra time, if you drive about a half hour further North, you'll hit Niagara-On-The-Lake, which is a gorgeous smaller town with nice shops and restaurants and stuff if you want to escape the tourists.