Late 70s and from 2004-2009 were some competitive times
'04 - Detroit
'05 - San Antonio
'06 - Miami
'07 - San Antonio
'08 - Boston
'09 - LA
Yup
2004-2012. That competitive period lasted until the early 2010s (2010,2011, 2012)
2010-11 was arguably the most competitive season in recent history. 8 teams could have won the Larry O’Brien title that year :
Dallas/Los Angeles/OKC/San Antonio in the west
And Boston/Miami/Chicago/Orlando in the east
And there were tough wildcard teams like the hawks, pacers and the grit&grind Memphis grizzlies (who made the WCF two years later as a 5th seed)
Three different champs in the early 2010s:
2010 Los Angeles
2011 Dallas
2012 Miami
(Looking back, Even the top-heavy mid 2010s werent that bad, 4 different teams won the chip, 2 from the east and 2 from the west)
2013 Miami
2014 San Antonio
2015 Golden State
2016 Cleveland
Kevin Durant joining the Warriors really made the 2016-17 and 2017-18 seasons pointless to watch imo. The warriors were too strong and stacked and miles ahead of any other team. They handled the west with relative ease (even went a perfect 12-0 playoff record in the west back in 2017 before the finals)and easily destroyed and outmatched the cavs in back to back quick finals. In a normal season, the 2016-2017 cavs win the chip and repeat as champions if they play against any another finalist team but unfortunately instead, they faced the warriors who were an all time great/legendary team.
Late 2010s/early 2020s parity:
2019 Toronto
2020 Los Angeles
2021 Milwaukee
2022 Golden State
2023 Denver
2024 Boston