Suggestions for a good English textbook ?

Hi everyone
I just have a question that needs your ideas to help me find out the answer. I am looking for a good commercial English textbook that can serve well in teaching 4 language skills that are reading, writing, listening and speaking. I am Thai and going to teach an English course for freshmen and the department needs the course to focus on integrated skills. Do you have any ideas about this? Some friends of mine who are teachers use Cutting Edge but they don't like it that much though.
Thank you very much for your help in advance.