This was an amazing show! So few shows really suck you in and keep you coming back even over a decade later - and do it in a way that you don't really feel like you've stepped into a time warp. The cast are people from big movies and TV shows - some who didn't make it until after leaving, while some had already made a big impression. Dr. Green was once our lovable friend from Revenge of the Nerds, Bennett was in Coming to America, we all know Clooney from everything, and there were huge stars as guests throughout the series such as Alan Alda from MASH, Mrs. Garrette from the Facts of Life, Ed Asner, Forrest Whitaker, Rosemary Clooney (George's Aunt), Lucy Liu, Miguel Ferrer, Tobin Bell from Saw, Sally Field, Michael Ironside, Ray Liotta from Goodfellas, and so many more. It was fun playing the 'where do I know that face from' game during all 15 seasons. While the last 2 seasons weren't their best, they did one fine job of closing most everyone's stories in the end. Very few shows have made the impact on viewers and actors like ER, and manage to do it for 15 years. You can feel the pain, the elation, and everything in between because they had one of the best casts of all time, while managing to stay reasonably accurate in the grand scheme of how real medicine works.