PROMPT 2:

 Admittedly, I am not much of an NHL expert. Or an SHL expert for that matter. So please forgive me for just going with the easy choice and choosing the Edmonton Oilers trading Wayne Gretzky to the Los Angeles Kings. I'm going with trade for how much it burned the Oilers fan base, with the Edmonton owner at the time Peter Pocklington being described in an article as being "burned in an effigy", with the Oilers 21 phone lines just blowing up with all kinds of threats and cancelations of season tickets. A member of the Canadian Parliament triee to get the federal government to block the trade, for goodness sake!

 It should be noted that Wayne asked for the trade, and in his first season with the Kings he won the Hart Thophy as the NHL's MVP for the 9th and final time. While the Kings would not win the Cup with Wayne, but he would lead them to 5 straight Playoff seasons and basically make Hockey popular in LA. The Oilers would win one more Cup in 1990 but thier dynasty would crumble without Wayne.