Eloy feels like a cross between say Genesis (concepts, melodies), Deep Purple (keyboards). The top album in IMHO is Ocean from 1977. Simply put: the rise & fall of Atlantis in 4 tracks totaling 44 minutes. If you like the classic progressive rock era (Pink Floyd, Genesis, Yes, King Crimson, ELP, etc.), the "spacey" kind, you will find this album rewarding and something you will go back to.
Below is the YouTube clip of the whole album, give it a whirl. Next albums I'd recommend in order: Dawn, Silent Cries & Mighty Echoes, Power & The Passion, Colors.
Personal note: I always buy my music because musicians need to eat too. Especially true where I listen to a lot of band which never make it to the mainstream, supporting them is quite important otherwise they'll just quit. And frankly that's theft anyway, regardless if it's from an evil faceless corporation :)