This is a great way to get to know the kids in your class and it is different then the usual "What's your favorite book? What's your favorite food?" worksheet. You can use this as an individual activity where students write out their train of thought and later share with the class, partner/group activity for your students to get to know each other, or as a whole group activity!
In my experience, the kids in my class ALWAYS want to tell what they have chosen and why, so this would be perfect for a first week activity! Plus, it easily incorporates writing. Also, if you teach ESL, this is an excellent way to get in some listening and speaking!