Dept. Heaven/Awesome Music

When Hayashi Shigeki and Adachi Minako get together for soundtracks, awesome things happen:

Riviera: The Promised Land

 * "Grim Angels" is the first battle song you hear, and gets reused when you fight
 * "Battle Against Demons", the generic battle theme. Especially the version used in the GBA PV.
 * "Inescapable!", has a catchy melody and is fast paced inducing the feeling of actually being cornered by enemies.
 * The Final Boss song was actually brand new in the GBA version, and it was so awesome that they had to make an arranged version.
 * "Dark Gate" is actually an arrangement of Heaven's Gate theme, made awesome and fitting for the final chapter.

Yggdra Union

 * The extended version of Yggdra's arranged theme.
 * Milanor's Leitmotif is pretty heroic and kickass.
 * Recruitable character Cruz has a pretty awesome theme.
 * Gulcasa's Leitmotif has undergone four official mixes (five as of the PSP OST release), and with good reason--it's just that badass.
 * Although being quite short, Mistel's theme is damn catchy and cool.
 * Cute Witch Pamela's theme is quite catchy
 * "We'll Never Fight Alone plays during the demo and is damned kickass.
 * The Royal Army's Leitmotif has many remixes. However Blitzkrieg will become an Ear Worm
 * "Battle on the Requiem" played during the final maps.
 * When the soundtrack for the PSP version of the game was finally released in Japan, a number of battle themes (Russell's, Aegina's, Gulcasa's, Nessiah's, and the generic Dragon General and Soldier themes) were extended or otherwise remixed. Said extensions and remixings are generally quite badass.

Yggdra Unison

 * Following in that tradition, both of Gulcasa's themes, "Blazing Emperor" and "Path of the King".
 * Both of Milanor's themes: "Towards an Ideal" and "In the Nocturnal Assault"
 * Yggdra's daytime theme "Under the Holy Sword".

Blaze Union

 * The short answer: Everything.
 * Youth Knows No Sin, Emilia's Leitmotif.
 * Bravely, If Roughly, Leon's.
 * The Limit of Wit, Jenon's theme
 * Powerfully, Fleetingly, Peacefully, Eater's theme.
 * It's back and you love it.

Knights in The Nightmare

 * Ep. I-II-IV Fantasia, a full-orchestral medley of two songs each from episodes I, II, and IV, culminating in a triumphant version of Maria's theme.
 * Knights in the Nightmare, the title screen music is so calm, soothing and sad.
 * Main character Maria's theme is kickass.
 * Battle at the Gate
 * Clash with Cursed Pisce (PSP version here)
 * Clash with the Sharpshooter Aqueline
 * Call of the Moon/Clash with the Werewolf Jamie
 * Clash with the Imperial Princess Alier (PSP version here)
 * Clash with the Dark King Zolgonark (PSP version here)
 * Battle in the Land of Cantolounn (PSP version here)
 * The DS version of Clash with the Servant/Devout Sacchito is mediocre, but its PSP counterpart is much better.

Gungnir

 * Gargandia 983, the opening movie theme.
 * The Chief Knight Robertus
 * "Raguel", the theme for.
 * Leonica and Daltanica, the theme for the final battle of the B route.

Gloria Union

 * Pinger's theme, "The Cat-Eared Pirate".
 * "Sweetly, Ferociously" (or Beatifully, Fiercely), the remix of Eater's theme.
 * "A Destroyer Clad in Gold" (or The Golden Destroyer), theme of this world's Yggdra.
 * "The Dual Pistols Sing in the Battlefield" (or My Two Guns Sing on the Battlefield), Elisha's theme.
 * "Brave!", Kamuru's theme. Make sure to turn the volume up!
 * The Seeker, theme of Gariored and Ashley.
 * Candy Power!, theme of Locomoco.
 * A Vampire Wielding the Demon Spear!, theme of Raspberry.