Pat Summitt caught me by surprise as well, despite knowing the health circumstances of her stepping down from the Lady Vols head coaching job.
Buddy Ryan however? Honestly, I never liked him. Like I said, I only knew him for his controversies. Yes, he was the mastermind of one of the greatest defenses of all time, the 85 Bears, and brought his defensive mindset with him to Philadelphia when he became the head coach, and for that, he goes down in NFL history. It's all the "other stuff" associated with him I don't like. For example, after shutting out the Dallas Cowboys on Thanksgiving in 1989 (full disclosure; I'm a Cowboys fan), Cowboys head coach Jimmy Johnson accused Ryan of putting bounties on Troy Aikman and Luis Zendejas; ironically, one of Buddy's twin sons would serve as the Defensive Coordinator of the Cowboys and label the Eagles the "All Hype Team" 22 years later. In 1990, he said through the press that the Eagles were going to beat the Washington Redskins so badly that they would need body bags. This may have been trash talk (a specialty of the Ryan coaching family, as Rex and Rob would ultimately prove later), but his words were metaphorically prophetic, as roughly 9 Redskins players left the game with injury, with RB Brian Mitchell finishing the game at QB. So he was a polarizing figure throughout his coaching career. His most controversial roster move was cutting Cris Carter during training camp in 1990. This move was routinely questioned and criticized as Carter became a Hall of Fame receiver with the Minnesota Vikings, until Carter himself revealed the truth; the real reason he was cut by Buddy Ryan is because he had issues with substance abuse, and this turned out to be a wake-up call for him to turn his life and career around.