By era (https://en.wikipedia.org/wiki/List_of_Who%27s_the_Boss%3F_episodes), I'm going to simply break things down by the variations of the theme tune (https://www.sitcomsonline.com/boards/showthread.php?t=397928) "Brand New Life":
Seasons 1 (https://reviewingeverytvshowiown.blogspot.com/2016/12/whos-boss-pilot.html)-2 (https://reviewingeverytvshowiown.blogspot.com/2017/01/whos-boss-charmed-lives.html):
zkD9wzrrhiA

The first version was used for Seasons 1-2. It was in the key of C and was sung by Larry Weiss.

Seasons 3 (https://reviewingeverytvshowiown.blogspot.com/2017/01/whos-boss-angela-gets-fired-part-1.html)-6 (https://reviewingeverytvshowiown.blogspot.com/2017/05/whos-boss-all-nighter.html):
vHWYAs0x90c

The second version was used from Season 3 to midway into 6 and was in the key of D and sung by Steve Wariner.

Seasons 7 (https://reviewingeverytvshowiown.blogspot.com/2017/05/whos-boss-ridiculous-liaisons.html)-8 (https://reviewingeverytvshowiown.blogspot.com/2017/07/whos-boss-savor-veal-part-3.html):
uHAbQx9qbi8

The third version was used toward the end of Season 6 up to the end of the series. It was also in the key of D and was sung by Jonathan Wolff.