Lest anyone get the idea wearing the NBA crown is an easy thing, remember:

There have been 18 expansion teams … but only eight of those franchises have won titles, 16 of them in total. Three of the eight franchises have won multiple titles (Chicago 6, Miami 3, Houston, nee San Diego, 2).

There were four ABA merger teams … only one of those franchises (San Antonio) has won a title; in the Spurs’ case, five (5) of them.
The remaining 45 titles have been won by eight franchises, all of which were in the league during the inaugural, 1949-50 season.

Five of those eight originally were members of the National Basketball League (1937-49) and have won a total of 25 NBA championships (15 of them by the Minneapolis-Los Angeles Lakers).

The other three were members of the Basketball Association of America (1946-49) and have won a total of 20 NBA titles (16 alone by Boston).
Bottom line: There are 10 expansion franchises (including Phoenix) that have NEVER won a title. And there remain three of the four ABA merger franchises (Indiana, Denver & (now, the Brooklyn) Nets) to NEVER win a title.

Other title-less expansion franchises beyond Phoenix, the longest standing of the group: LA Clippers (nee Buffalo-San Diego); Cleveland; Utah (nee New Orleans); New Orleans (nee Charlotte); Orlando, Minnesota, Charlotte, Toronto and Memphis (nee Vancouver).