The Flaming Lips were the first band I though of. I can't think of another band who has transformed so consistently throughout their career.
Hear It Is (1986)
Oh My Gawd!!! (1987)
Telepathic Surgery (1989)
In a Priest Driven Ambulance (1990)
Hit to Death in the Future Head (1992)
Transmissions from the Satellite Heart (1993)
Clouds Taste Metallic (1995)
Zaireeka (1997)
The Soft Bulletin (1999)
Yoshimi Battles the Pink Robots (2002)
At War with the Mystics (2006)
Embryonic (2009)
The Dark Side of the Moon (2009)
I enjoy the first couple, but they are not of the same caliber as their later work. In A Priest Driven Ambulance started to show what they were capable of. My favorites are Transmissions... (6th), The Soft Bulletin (9th) and Embryonic (12th), but I love them all after ...Priest..., except for At War with the Mystics. Some great songs, but as an album, it just didn't work for me.
The Lips have been through a lot of changes over the years. I was at their first three or four shows and they were fun as hell, but boy were they awful! (In a good, humorous way.) They were always cool guys but seriously, when they first started playing live around '82-'83 they were such a glorious sloppy mess.
They did a couple of free-form, psychedelic Pink Floyd-like improv jams, a few really poorly executed covers (Who, Zep) and since their repertoire was so llimited, they'd do The Batman Theme (from the old 60s TV show) sometimes as much as three times a set. They got serious, and seriously good, really quick though.
Growing up with them back then, those early albums mean a lot to me and my old friends. They've lost members and added new ones over the years (Wayne and Mike Ivins are the only original members.) They are fearless and let me tell you, Wayne is probably the single most creative individual I have ever known. His mind is perpetually on fire dreaming up new music, new approaches to music, new stage shows, artwork, etc.
Likewise, Steve Drozd (who came along for the
Transmissions album and has been a centerpiece since then) is probably the finest musician I have ever been around or seen in action. The guy can play, literally, any instrument you hand to him. He can get something musical out of it. I've never seen anything like it. He could build a symphony from a beer can and a blade of grass.
I love all their albums (like you I thought
Mystics was their weakest) but
Priest, and the albums they made with Ronald Jones are highlights to me. I got to be in the studio with them for some of the recordings back then and this is a band who takes great pains to really craft ALBUMS--albums with dynamics and different emotions and sonics. They are just endlessly creative and willing to get as experimental as can be while still being able to put forth quirky, catchy songs. There's really nobody else like them.