From Albedo 0.39, "Alpha". By itself it's a great piece of music, but it becomes pure awesomeness when combined with the sound of the late, great Carl Sagan's voice. "Pulstar" is ridiculously catchy. There's also a fairly awesome trance remix of this by Majestic (12), however, good luck finding it, as it wasn't commercially released and all filesharing networks carrying it have since been shut down.
The title track from Spiral combines a grand, cosmic melody with strange, disorienting "spiralling" sounds. It was the artist's first composition to feature the Yamaha CS-80 synthesizer, an instrument which he would use to great effect on all his subsequent albums. "To the Unknown Man" is divided into three parts, the first featuring a slow pulse and guitar-like melody, the second strings, and the third a rock beat and organ chords. And it is epic.
If you're in the mood for something a little more avant-garde, here's "Beaubourg". Essentially an extended CS-80 demo, it's full of weird and unnerving sounds, making it possibly the trippiest work ever created by the composer.
China combines elements of traditional Chinese music and 1970s electronica to great effect, most prominently on "Chung Kuo" and "Himalaya".
Mask is classically inspired and choral with all the grandeur of something like Heaven and Hell or Ignacio, but Darker and Edgier. Of particular note is "Movement 4", which features complex percussion similar in feel to West African tribal drumming.
From Voices, "Ask the Mountains" features inspiring vocals by Swedish singer Stina Nordenstam, while the title track is an absolutely spectacular bit of classically-inspired electronica in the same vein as "Conquest of Paradise".
From Oceanic, "Fields of Coral" is a serene and relaxing bit of ambient music evocative of the wondrous worlds that lie beneath the sea.
The documentary De Nuremberg à Nuremberg would probably be only half as frightening and emotionally impactful as it is without its soundtrack. In fact, any of the documentaries by director Frédéric Rossif on which the Greek composer collaborated would not have been even half as good without his music.
With The Bounty, the composer manages to make a modern-day electronic score work in a period film just as he had done three years earlier in Chariots of Fire. The end credits theme is especially memorable with its melancholy piano melody and ethnic-sounding percussion effects.
The 1975 Mexican film ¿No oyes ladrar los perros?, also known as Ignacio and based on the short story by Juan Rulfo, isn't exactly well-known outside its country of origin, but its soundtrack is among the Greek composer's greatest accomplishments.
The composer's soundtrack to the 1983 Japanese film Nankyoku Monogatari, better known as Antarctica and later remade as Eight Below, is epic as hell.