The five incredibly awesome end credits by Jerry Goldsmith which also served as concert suites:
Star Trek: The Motion Picture. When it comes to popularity, the inventiveness of the instrumentation, the epic grandeur of the scoring and the benefits of modern recording, this is quite simply Goldsmith's greatest score.
Star Trek V: The Final Frontier. Another hugely enjoyable Goldsmith score in which the main theme sandwiches the Klingon theme. Goldsmith even utilizes a wailing electronic ram's horn to emulate the distinctive scream of a large bird for the villains' bird-of-prey.
Star Trek: Insurrection. This pretty and unassuming theme sandwiched in the middle is a sweet little thing, reminiscent of the kind of lofty strings and woodwind in Rudy and several other tender Goldsmith character scores, perfectly evoking the bucolic idyll of the film's locale. (Watch out, he's got an oboe and he's not afraid to use it!)
Star Trek: First Contact. Just the noble and uplifting horn theme bristling with awe inspiring thoughtful woodwinds and strings must surely rank as the most moving musical moment in any of the Star Trek films. Acknowledged by the maestro himself as his best Star Trek score.
Star Trek: Nemesis. The maestro's last venture to the Star Trek franchise, where "Blue Skies" is heard on a piano, and it slowly builds up into a full blown Star Trek March.
Quite a few of the musical cues in this film would go on to become Star Trek staples. The "Klingon Battle Theme" from the start would go on to become the primary Klingon theme (and Worf's leitmotif), several of the major musical cues would be referenced again and again in later works... and oh yeah, the main theme to the movie became the theme song for Star Trek: The Next Generation, was used as the closing theme for some of the TNG movies, and was also recycled as the opening theme for Star Trek V: The Final Frontier.
The film score received an Oscar nomination, and one of the most beautiful pieces from the film, "Ilia's Theme", is all but forgotten by most non-Trek fans. In fact, it was played as an overture over a black screen before the film began (much as Ligeti's "Atmospheres" played before 2001: A Space Odyssey.)
The La-La Land three-disc expansion is a must, as not only does it provide the complete score for the first time, it's chock full of alternate takes, early versions of several tracks (before Goldsmith came up with a proper theme), a few bonus outtakes, and the original soundtrack album tracks. Throw in a funky disco pop version of the main theme and "A Star Beyond Time", a version of Ilia's Theme with lyrics sung by Shaun Cassidy.
"The Enterprise," the stunning cue that plays during the "Kirk looks at the Enterprise for a thousand years"note Well, six minutes scene, is a Moment of Awesome for both Jerry Goldsmith and the orchestra itself—scoring sessions generally require multiple performances of a track, but they nailed it on the first take. This came after the music was rewritten, as when Goldsmith started the score, they did not yet have a definitive title theme. The original piece had been written with a nautical theme, and would not be completely out of place in a Horatio Hornblower film, but it didn't feel like Star Trek. That said, once they had their theme, they nailed it.
Wrath of Khan's Surprise Attack, particularly the cellos at 3:22 onwards - the track gives an utter sense of terror and dread at being ambushed.
James Horner is a genius for knowing when not to bomb us with orchestration. The silence during the climactic chase in the nebula is downright frightening! Which of course makes the actual orchestral bombing all the more satisfying when Enterprise gets the jump on Reliant and the climactic battle begins in earnest.
There are long stretches without music, and the negative space really has an impact too. Of the 113 minute runtime, only 100 minutes have music in them. (The 13 minutes of the score that weren't included in the original soundtrack release were the Genesis Project Film music, and the horror style moments with the Ceti eel and the search of the Reliant.)
While Cliff Eidelman's score is awesome in general, "Overture", played during the opening credits especially qualifies as such simply because it builds to a climax that is topped off with Praxis exploding. Meyer wanted him to use Gustav Holst's The Planets as an inspiration; "The Overture" uses "Mars, the Bringer of War" as its basis. The Overture was used as a temp track on the 2002 Spider-Man, for when the Green Goblin first makes his appearance over Times Square. It's a go-to temp track for picture editors who need a low ominous build. Director Nicholas Meyer had wanted James Horner to return as composer, but the production could not afford him. Meyer is reported as saying that Horner was hired for The Wrath of Khan because they couldn't afford Jerry Goldsmith, but Horner had become such an in-demand composer in the interim that they couldn't afford Horner for this film!
"Clear All Moorings" is a light, warm piece as the old crew of the Enterprise enjoy one last launch, the music swelling as Scotty watches the impulse engines humming.
The sweeping music that plays as Kirk, McCoy, and Martia make their way across Rura Penthe.
"The Battle for Peace" accompanies the entire battle over Khitomer. In particular, the slow but steady build up in the track as the Enterprise takes more and more damage, and Spock and McCoy are desperately trying to finish modifying the torpedo to take out Chang's modified Bird-of-Prey.
Regardless of how one feels about Star Trek: Generations, it is hard to deny that the score, one of composer Dennis McCarthy's few cinematic offerings, is first-rate. For example, the haunting "The Nexus/Christmas Hug" track, where Picard finds himself in a comfortable home with wife and children, with subtle discordant musical cues letting him know that all is not right. It's warm and heartbreaking at the same time.
The main theme "Enterpising Young Man", especially in the opening credits. Something about that crystalline, somber yet uplifting horn solo sends chills down your spine every time.
Especially the brief variation that plays on the drill platform when Sulu whips out his folding katana, throws off his helmet, and looks ready to rumble.
Michael Giacchino's work for Star Trek (2009) contains many, many notable examples of orchestral awesomeness, such as the beautifully heart-rending "Labor of Love" (played during George Kirk's Heroic Sacrifice), "Hella Bar Talk" (Kirk contemplating his future before joining Starfleet), "Enterprising Young Men" (accompanying the shot of the alternate-reality Enterprise in spacedock) and, most of all, his glorious rendition of the classic Trek theme in "End Credits."