Ever since I finished Fringe, I've been meaning to go back and rewatch it from the beginning -- it seemed like a show that would benefit from watching with the full context in mind. Recently, I finished the first season (except for that random "mystery of the week" ep that got slapped on out of order at the end), and so far it has not disappointed. Spoilers, not just for the first season but for the entire series.
( Cut for spoilers, cut cut cut )