My favourite teacher of all time was my Spanish teacher José here on italki. He was always well prepared, very flexible and adapted his approach to his students' needs, he used technology to teach, he had worksheets and class notes in google docs, provided personalised flashcards, recordings of the classes, sometimes video feedback to written homework and of course his website (https://teacherjose.com/) where he offers a podcast, plenty of audio and video material, interactive exercises and  much more. Currently, he's taking a break from teaching but is focusing on developing his website even further. But occasionally he offers free interactive Facebook live stream classes (https://www.facebook.com/spanishteacherjose/) and I'm always astonished at his ideas.