Black Lotus' theme, "Alert Sign", first heard in Episode 5. During her fight with Yellow Radio in Episode 11, it gains a kickass beat that firmly cements her reputation as one of the best Burst Linkers currently in existence.
Most of the music for the AIR game was considered good enough to be used directly the anime release as well—and with very good reason. Especially noteworthy is the track "Aozora" (Blue Sky) sung by Lia, whose mournful vocals set the perfect mood for the already very sad ending. The instrumental version is used all through the series to maximum effect as well.
The anime and game opening "Tori no Uta"definitely deserves a mention.
Aside from copious amounts of excellent Scenery Porn, ARIA has an impressive soundtrack, consisting of slightly classically tinted, soft pieces that fit the mood of the series perfectly. Most of the tracks are produced by Choro Club, who also did excellent work on the second OVA release of Yokohama Kaidashi Kikou.
"Tenki Ame" is probably one of the best instrumental songs in the series. It just has that warm, fuzzy, Heartwarming feel to it. They played it when they found Maa.
Still the most beautiful piece is probably the opening theme of the AriettaOVA, performed by SONOROUS, with its slow and immensely melancholic melody. It is a strong departure from the more lighthearted tunes of the other OPs and sets the mood for the rest of the episode extremely well.
And while we're at it Yokohama Kaidashi Kikou deserves its own, proper entry. When Nai takes Alpha up in his airplane in particular, but there are other moments that qualify too. Not to mention pretty much everything that applies to ARIA in this trope carries over to Yokohama Kaidashi Kikou as well.
It's a fanwork about a fanwork, but the music in this video definitely qualifies. It weaves together different Vocaloid pieces in a way which is smooth and beautiful, and the "Veneziano" measures are amazing! Which isn't mentioning the video itself and how cute and yet sad that it is.
Russia's character song and the song that plays in the anime (Episode 89) when Russia first encounters Lithuania.
It may not be official, but this fusion of Japan's Image Song "Osoreirimasu Sumimasen"/"Excuse Me, I'm Sorry" and China's Image Song "Ni Hao Chuugoku"/"Hello, China" titled "Sumimasen Chuugoku"/"I'm Sorry, China" needs to be mentioned.
Speaking of which, the Kuricorder Quartet, who did the background music for the series, has an epically cute rendition of the Imperial March. Yes, that Imperial March.
The Maya songs are just awesome for what they represent and when they're used.
Look, have you heard the soundtrack? It's pure cute, quirky, sometimes sad awesome—in short, it's Azumanga Daioh. For example, "Shingakki" (sometimes referred as "Osaka's theme" or "Sakaki's theme") in its many variations. The perfect slice-of-life anime background music piece.
The six main characters' image songs are no slouch either!
"Running On" from Episode 9. That music makes for the most epic game of basketball ever, even if Rouge does get hit by a ball halfway through the song. Especially because the length of the game is defined by the song.
In the second season, we get an insert song, "Kagayaku Sora no Shijima ni wa" that is also performed by Kalafina. It's just as lovely and atmospheric as their previous song, "Lacrimosa", and also downright depressing in context.
The 2nd opening theme, "tRANCE" by GRANRODEO, is 100% pure awesome, with metal-esque riff, some awesome soloing, a hooky chorus, and liberal Engrish ("Death Through Trance" indeed). After the cheesy synth-pop 1st Opening Theme this is downright refreshing, just like "WHAT'S UP PEOPLE" was to Death Note.
"Destiny -Taiyou no Hana-", the opening theme for Black Jack 21. Doctors, apparently, get really epic theme songs. Similarly, the background song "Miracle". Whenever you hear this track, you KNOW that lives are going to be saved.
The original soundtrack is full early hard-rock and glam-metal inspired tracks that are quite reminiscent of the music of Deep Purple, Led Zeppelin, and Queen, such as "Freddy'sTheme" for this character.◊
"Senshi Yo Tachiagare" from Cybaster/Cybuster. The lyrics are already awesome (seriously, hear it and read the translation). Now hearing it live, there are no words that can tell about it. Now hearing it in an acoustic version is simply death...
For Demashita! Powerpuff Girls Z: While "Rise of Him" seems to be a repetitive techno song like the rest of the soundtrack at first... Cue the organ and the strings. If it doesn't seem like CMOA at first, try listening to the rest of the soundtrack and coming back. Also, "Touch Me!", the instrumental of which plays either when the girls transform as a group or when the villains are going to get their butts kicked. When the version with lyrics starts playing, the villains really should take that as a cue to run for their lives.
Dennou Boukenki Webdiver is a lesser-known sci-fi series from 2001. Nonetheless, both the opening "Diver 2100" and the ending "Together" deserve a special mention.
"Ryokushoku no Kioku/Green Memories", which is first heard with beautiful scenery as our protagonist has a lovely dream of "being whole again." It plays again later on, when said protagonist is riding on her motorcycle thinking about the man who loves her. She tosses her arms into the air and says (paraphrased): "If there is someone that can find redemption in me, then why can't I find redemption in them?" It is one most beautiful scenes in the series, and the lovely piece only amplifies it.
ef: A Tale of Memories has the ending theme for Episode 2, "euphoric field", which turns out to be the opening for the rest of the series and also what comes out when you take the first letter of each episode's title. The song itself is mostly correct, if mispronounced Engrish, and was performed by Tenmon, of 5 Centimeters per Second fame. Tenmon also composed the rest of the series' incrediblytouchingsoundtrack. The most awesome part is the opening to Episode 12, which was exactly the same as the other openings, except the song was in Japanese and the visual symbolism was completely changed. When you think about how this must have affected the primary audience, who now understand the lyrics, it becomes doubly awesome.
It's not just those songs; the soundtrack, composed by Naoki Sato, is a delicious mix of music that not only fits the different moods of the series, but can move the listener to tears with its pure awesomeness.
Only one anime opening theme (besides Baccano's Guns & Roses) has even challenged Tank's position as the best jazz opening of all time: "Boomerang Boogie" from Gad Guard. It's more swing than bebop, but when it swings, it SWINGS!
Gantz, despite being absolutely gruesome and pointless, has the annoyingly catchy, Engrish-laden Super Shooter to add to the repotoire.
The GaoGaiGartheme song, "Yuusha-Oh Tanjou" is one of the catchiest pieces of music ever, successfully emulating the classic Super Robot style without feeling dated for its time, or even ten years after its time. It also makes it easier to remember for those who call it a tongue-twister.
Also. Yuuki Aru Tatakai, the track reserved for battles such as the one with EI-01, the Primevals, and Mamoru.
The themes for Soldat J and King J-der are also pretty awesome. In fact, ANY music, used as the motif for ANY main character/ robot, 99.99% of the time, it's Awesome Music. However, the themes for the Goldion Hammer and the Goldion Crusher in the OVA are probably the most epic ones there are.
While not even remotely "hell yeah!" awesome, kudos have to be given to the track on the other end of the spectrum...Guy's Theme. It makes you want to cry, give him a hug, and salute him all at once.
The saddest song on the soundtrack, though, is the one for the other protagonist. Mamoru's Theme is such a beautiful, sad song, and the show knew just WHEN exactly to use it. Mamoru's Character Development after The Reveal, the exposition about the fate of Mamoru and his replicant at the beginning of Episode 8 of FINAL, it justs works so well with what's going on.
Last, but not least, Saikyou Yuusha Robo Gundan. "The Strongest Robot Brave Corps" is the hotblooded leitmotif of the Braves. Every time this song is playing, one of the Braves—or all of them—is doing something awesome.
The credits theme for the movie adaptation of Project ITOH's novel Genocidal Organ. Due to studio Manglobe's bankruptcy, the movie was delayed, but the song was released in late 2015, "RELOADED" and it may well be one of EGOIST's finest works.
Genshiken's first ending theme "Biidama". It isn't bombastic rock or an insanely catchy bubblegum J Pop hit—it simply captures the bittersweetness of going to university and making friends,then having to leave both of them behind. It's even more heartbreaking with the translated lyrics. Saori Atsumi, take a bow.
While not badass like the other examples, the "Yorozuya Blues" that played while Gintoki and Otae pass each other in the rain as he goes off to fight Benizakura against her orders is pretty awesome (this is a slightly different version than the one from the show). It's laid back and melancholy and perfect.
Girls und Panzer has several well done versions of military marches, but the seiyu singing the Soviet-era song "Katyusha" became an instant fan favorite around the world.
It's a shame that there are no full versions of the really awesome OP for the original Glass Mask series, "Garasu no Kamen" by Mariko Ashibe. Still, the TV version gives a glimpse of what a lovely song this is.
The Delgados' "The Light Before We Land", used as the opening theme in Season 1, is a mesmerizingly melancholy song that perfectly sets the mood of the show. From the same album, "Woke From Dreaming", used as an insert song in Episode 7, is also a beautiful keeper.