The New York Islanders and New York Rangers have put forth contrasting decades. Initially, the Islanders were not great. They missed the playoffs five times and did not get past the second round three out of the four times that they did make the playoffs.
They are now one of the best teams in the NHL (thanks primarily to their head coach, Barry Trotz, who is the best coach in the league) but that definitely was not the case for the vast majority of the decade.
The Rangers were the Islanders’ antithesis. They are currently approaching the tail-end of an impressively quick rebuild, but they were one of the most dominant teams in the league for the majority of the decade.