Is it possible to get perfect score in TOEFL's Speaking Question Type 1 (Personal preference) without using examples?
I'm not sure about the relevancy of TOEFL prep questions on the Academia Stack Exchange (you're probably better off using a forum like this one) but to answer your question: The official guide to the TOEFL published by ETS states:


  This question will always ask you both to describe something (for example, an  important event, a favorite activity, an influential person) and to give reasons-to  explain why the event was important, why the activity is one of your favorites,  how the person influenced you, and so on. Be sure to respond to all parts of the  question. Your response should include specific details and/or examples because they will make your description informative and your reasons comprehensible. 


If you think you can make your description informative and your reasons clear without concrete examples, do so. In my opinion, it is better to stick the official guide's recommendation. However, it does not specify any specific number of reasons and examples. I got a full score and I only gave one reason but elaborated on it with a specific example and a detailed argument.