With the Indians off on Thursday, you made have had time to notice that despite it being the second half of June, there was another Cleveland team playing. The Cavaliers won Game 6 of the NBA Finals in impressive fashion, and despite being heavy underdogs heading into the series, they're now one victory away from their first championship. Game 7 is Sunday night. Meanwhile, the Indians find themselves in first place in the AL Central, a division they've won more times (seven) than any other team, but haven't taken since 2007.
Cleveland sports haven't been riding this high in a long, long time.
(Even the Browns, by not having played a game yet, are at what's likely to be their highest point of the year.)
The last Cleveland championship came in 1964 when the Browns defeated the Baltimore Colts in the NFL Championship Game. I think most of us would agree that one team winning a title is better than multiple teams playing well but not winning a title, so I think it's reasonable to say that December 27, 1964 has been unmatched for Cleveland sports in the more than fifty years since then.
In terms of the city's best years for sports, the Browns and Cavs both made the postseason in 1985, 1988, and 1989, but the Cavs lost in the first round each time, and the Browns won only one playoff game in those years. The Cavs and the Indians both made the postseason in 1995, 1996, and 1998, but again, the Cavs lost in the first round of the playoffs in each of those years. (Meanwhile, the Browns and Indians haven't both made the postseason in the same year even once since the city's last championship.) The city's most successful year since that Browns title was 2007, when the Cavs reached their first NBA Finals, and the Indians won the division and made it as far as Game 7 of the ALCS.
That was a good year for the city, but by the time the Indians were in that ALCS, the Cavs had long since been swept in those NBA Finals. The peak moment of that year would have been Saturday, June 2, the night the Cavs finished off the Eastern Conference Finals by beating the Pistons in Game 6, while the Indians held onto a 3.5-game lead in the AL Central. Every game of that Cavs/Spurs series brought the city a little farther from a title.
The Cavs reached the Finals again last year, and took a 2-1 lead, putting the city its closest to a title since the Indians were in Game 7 of the World Series in 1997. The Indians had a losing record and were well behind first place at that moment.
The peak moment for Browns/Cavs would have been the morning of January 14, 1990. The Browns were set to play in the AFC Championship Game that afternoon, and the Cavs were 26-7, best record in the NBA.
The peak moment in the last half century for Browns/Indians, because the Indians were always behind in the 1995 World Series and the Browns didn't exist during the 1997 World Series, would have been Tuesday, October 17, 1995, the night the Indians clinched their first AL pennant in 41 years, while the Browns were sitting at 3-3, months away from being ripped from the city.
The peak moment for Cavs/Indians, I would argue, is right now, and because it's the first time the city has been one win away from a title while another of the city's teams also has a winning record, I would argue right now is the city's peak sports moment in more than fifty years.