Some of the NHL teams that eventually broke through and won the Stanley Cup:
The poster boys. They were consistently one of the top teams in the NHL with Alex Ovechkin and three Presidents' trophies for most points in the league, but they could never get it done. Sidney Crosby and the Penguins usually blocked their path. The Caps were built to win the Cup in the 2016-17 season. They didn't. They weren't supposed to win it last season. They did. They beat their demons and got past Pittsburgh and rolled from there, including past Tampa Bay in the Eastern Conference final before topping surprising Vegas for the franchise's first Cup.
New York Rangers
The Broadway Blues endured one of the more infamous wall-banging streaks in NHL history, a 54-year Cup drought, despite powerhouse teams in the early '70s. Bobby Orr, Phil Esposito and the Bruins were in the way. It took near misses and some years of lousy hockey, but eventually, behind the prodding of coach Mike Keenan, super captain Mark Messier, Brian Leetch, Mike Richter and, yes, Stephane Matteau (Matteau! Matteau!), the Rangers won it all in 1994.
One of the more talented teams in the league in the 1980s couldn't get past its Alberta nemesis, Wayne Gretzky and the Oilers in the West, and when the Flames finally did in 1986, the Canadiens were there to beat them in the Cup final. In 1988, Calgary won the Presidents' Trophy for most points in the league, but it was swept from the playoffs by the eventual Cup champion Oilers. Calgary finally broke through in the 1989 Cup final, defeating Montreal. Calgary's coach was future Lightning coach Terry Crisp. Note: The Flames have been to the final only once since 1989, losing to the Lightning in the 2004 final.
They were a Cinderella when they rode goaltender Jean-Sebastien Giguere to the 2003 Cup final. They fell back the next season but kept building. In 2006, they fell to the eighth-seeded Oilers in the Western Conference final. In the offseason, the Ducks added All-Star defenseman Chris Pronger to go with solid scoring lines, and it paid off with 110 points en route to beating the Senators to win the 2007 Cup.
Detroit Red Wings
They won the Cup in 1955 with Gordie Howe, then went silent — the "Dead Wings" era. Under captain (and eventual Lightning GM) Steve Yzerman and an influx of Russian stars, the Red Wings ascended but were swept from the Cup final in 1995 by the Devils. In 1996, Detroit won a league-record 62 games but lost to the eventual Cup champion Avalanche. Finally, having added Brendan Shanahan and Larry Murphy, Detroit won it all in 1997 by sweeping the Flyers, the first of consecutive Cups. It swept the Capitals in the '98 final.
Yes, they won the Cup twice in three years in the early '70s, but they were on the outside looking in after that, throughout the entire Ray Bourque era (1979-2000). They were close with two losses to the Canadiens in the final (1977, '78). In 1988 and 1990, they fell to the Oilers in the final. Then they couldn't get past Mario Lemieux and the Penguins. They blew a 3-0 lead in a playoff series against the Flyers. It took 39 years for Boston to get it done, with Tim Thomas in goal, beating the Canucks for the Cup in 2011, after edging the underdog Lightning in seven games in the Eastern Conference final.