My main resources in China have been the New Interchange series. I especially like the 'Passages' books which I guess are aimed at Upper-Int and Advanced. I dont use these religiously and I tend to chop them up and cut and paste the best parts of each section to make my own lessons.

I also used the 'Face 2 Face' series with some success. They offer a good blend of skills and language points and I found my best lessons came from using these books. I also think they were the most useful for my students as they offered a good balance between all the skills, and had good topics, lexical items and pronunciation tasks.

My final resource that I use often isnt from a textbook, but is a series of lesson that can be downloaded from the Guardian Weekly website. The site contains lesson for both advanced and pre-int students and I have downloaded 25 of each which I can use in rotation in my classes with minimal prep. Being familiar with these lessons I have also found a few additional activities to supplement them. If you want to try these, google 'Guardian Weekly' and sign up (just an email addy and password) to download the lesson PDF's from the 'teaching english' section.