The Great Wall of China is, well, really great! I would love to see the tourist numbers for various parts of the wall, since I'm pretty sure the hoards go to Badaling, which is closest to the tourist hotels of Beijing. I haven't been myself so it's a little unfair of me to knock it, but it just doesn't appeal to me. I don't want to be overrun with other tourists and peddlers trying to sell me trinkets and sell me photographs.
If you want a more authentic Great Wall experience, I strongly suggest you go a bit further out, such as Mutianyu (pictured here), or Jinshanling or Simatai - all parts of the wall I've been to. You'll find relatively few tourists, amazing scenery and feel like you're actually visiting authentic parts of the Great Wall because you are!
There's probably some other great sections of the wall that are less common to visit, and hopefully I'll visit more of the wall someday. I've been to China twice so far, and both times I made sure to visit part of the wall. It's like going to Paris and not seeing the Eiffel Tower, you just have to visit and experience it for yourself.
The Great Wall at Mutianyu, a UNESCO World Heritage Site.