For myself and many other ELT professionals, Stephen Krashen is a legend. In the words of Wikipedia, for instance ‘He is credited with introducing various influential concepts ... including the acquisition-learning hypothesis, the input hypothesis, the monitor hypothesis, the affective filter, and the natural order hypothesis’. So naturally, he is a big pull at a conference.
Carol Read’s plenary at TESOL France was titled, ‘Reflections on How to be a Highly Effective Teacher’. I’ve seen her give a number of conference presentations, but for me this was the best – a broad view of the field underpinned by good references, and a vivacious delivery.