I heard plenty of Chinese talk about Guilin as the most scenic destination in China. I have agree that it is quite scenic, but I did see much more appealing scenery in northern Sichuan and Xinjiang (I enjoy snowcapped mountains).
Here is one view of Guilin. Note: there was a constant light rain, that haze wasn't pollution-induced.
The mountains of Guangxi province are probably the most recognizable sights of China--they've been painted uncountable times throughout the centuries. Before visiting Guilin and Yangshuo, I had never seen mountains like these--I found them fascinating. Unfortunately, the weather didn't cooperate and we were limited in our hiking efforts to the main tourist attractions that had stairs and railings.