Well, if you want a comprehensive list of the good tunes of modern Trek TV shows:
-TNG had some catchy stuff in its first three seasons, but anything after The Best of Both Worlds is totally forgettable.
-DS9 had some good tunes during certain Dominion War episodes, The Siege of AR-558 being noteworthy.
-Voyager's best piece of background music is Species 8472's theme in Scorpion, though the action music played during the later seasons is okay though seriously overdone.
-Enterprise's background music was less bland than the previous shows, though none of it really stands out. The Mirror Universe theme definately, and I remember season 4's Vulcan arc having an interesting sounding guitar tune whenever Captain Archer met with Surak. But otherwise, meh.