Books and Resources

There are dozens of ESL books that are available to us tutors. Books we can use for teaching different courses and that are suited for every level. Each book is unique and filled with easy to understand lessons and fun activities for your students. Choosing a book to use in class needs thoughtful consideration because it is one of the most important tasks a tutor needs to do. First of all, evaluate your student. Factors to consider are his age, level and his purpose for learning. Second, based on your evaluation, are you going to teach based on a syllabus or core textbook series with leveled sequencing (from low beginner to advanced), or focusing on a specific skill is your target? And finally, will supplemental texts be necessary?
Some of the books I have used for my lessons are Side by Side series  and Grammar Time for grammar lessons, Interchange series for comprehensive skill activities, and Can You Believe It? for a take on idiomatic expressions and short, interesting stories that facilitates discussion. I have yet to remember the books I used when I taught in an offline academy a few years back :)
What about you? What books have you used or are using now?