Which is the nicest hotel in Chengdu, Xian, Zhengzhou, Taiyuan, Beijing an Tianjin?

I wil be trveling to china in a group of 7 adult, could anyone recommend the nicest hotel (not necessary the expensive one) in Chegdu,xian,zhengzhou,Taiyun,Beijing and Tianjin where we will stop over during our trip in March 2011.