Well, only by one. TNG was just one short of that: McCarthy, Ron Jones, Chattaway, Fred Steiner, George Romanis, Don Davis, John Debney. DS9 also featured seven: McCarthy, Chattaway, David Bell, Paul Baillargeon, Debney, Richard Bellis, and Gregory Smith. VGR had the fewest -- the four regular composers did all the episodes, with nary a guest composer in sight. Though you could add Jerry Goldsmith as the composer of the theme. (I don't count him and Courage on TNG because they didn't work directly for that show. Anyone know if Diane Warren was directly involved with arranging the theme for ENT?) And of course you specified spinoff series. TOS had the most composers: Alexander Courage, Fred Steiner, Gerald Fried, George Duning, Sol Kaplan, Jerry Fielding, Joseph Mullendore, Samuel Matlovsky, and Wilbur Hatch. (Hatch didn't do any full scores, but he contributed some original compositions here and there, not counting songs.) Of course, the shortest-running series of all, and the one with the fewest composers (Ray Ellis and Norm Prescott, under the pseudonyms Yvette Blais and Jeff Michael), was TAS, but I consider that more a continuation than a spinoff. You know, it's sad that Star Trek has never had a female composer, unless you count Diane Warren. Even "Yvette Blais" was really a man.