By creating and developing materials whose properties could be fully characterized, Professor George W. Gray has played a pivotal role in advancing our knowledge of liquid crystal states of matter. To honour him on his birthday, I briefly sketch some of my experimental results where the purity and stability of his cyanobiphenyl establishing new physical phenomena: the first re-entrant phenomenon in physics (1975, 1981) and the recent resolution of the nematic-smectic A transition order (1989, 1990). Even today, George Gray's liquid crystal materials are outstanding model systems for building physical intuition of generic non-linear, non-equilibrium problems, one of the most exciting frontiers of physics research today (1991, 1992, 1995). compounds played a crucial role in