1994 Montreal Expos
There is a question with 2 different answers. That question is: When were the Montreal Expos the closest ever to a World Series? Well, there are technically 3 answers if you count when the franchise became the Washington Nationals, in which case the answer is 2019...but we're talking about just the Expos.
The first answer is officially the right answer: 1981. They took the Los Angeles Dodgers to the decisive winner-take-all Game 5 of the NLCS, but fell short and never again made the postseason. The other answer is 1994.
The injustices of the 1994 season have been covered in total before. When the season was cancelled, the Expos were 74-40 and in first place in the NL East with baseballs best record, helping Felipe Alou get voted as Manager of the Year. They were 6 games ahead of the Atlanta Braves, and while nothing is assured in baseball (especially when it came to fighting off the Braves for a division title in the 90s) the popular opinion is that there was something special about the 1994 Expos that said they would finish the season on top, or at least holding the Wild Card.
The World Series that season was cancelled, as well as all of the playoffs. The Expos were hosed out as they were expected to go all the way. The fantasy World Series people make up in their heads were the Expos vs the New York Yankees, who were also a suffering team (at the time...Lord knows the Yankees haven't suffered since the strike). But while the Yankees came back in 1995 and began a major resurgence, the Expos...well...
The team ownership was cheap. They had one of the lowest payrolls in baseball, which helped endear them to fans in '94. But when the strike ended and teams needed to figure themselves out for '95, the penny pinching owners realized they had a lot of stars who wanted to get paid. A fire sale ensued, and by 1996 the team was a joke again. They could barely sniff a playoff run for the next several years and before long they were packing up to move to Washington.