I am a newbie, I have 3 albums and their DVD.
I heard that Space Revolver is their best album, you might want to get that one.
I heard 2 epics of Unfold the Future in the live DVD .. I have to admit that 'The truth will set you free' may be one of the best modern epics of all times. I do not know if the rest of the album has that quality.
Stardust We Are is very important for me (the first album I reviewed), because it's my first flower kings disc I got, and it made me realize the 70s-style prog is not dead. It is a double album, but I feel the second disk is much weaker than the first. I still recommend it. The music is very diverse here, so you might get a general idea of all the styles the band plays.
Adam And Eve may be their most accessible one, and they sacrificed virtuosity for song writing. It is controversial, so beware.
Rainmaker is probably their weakest album, many of their jams seem pointless here for me, and the songwriting leaves something to be desired. You will not like this album's lyrics.
Edited by Zitro