Good start – I liked Macdonald and Giles; “Birdman” was terrific.
I have a long list, of course. 
Twelve Dreams of Dr. Sardonicus – Spirit. A truly great album by a criminally neglected group.
Renaissance. This is the original incarnation of the group, a spinoff of the Yardbirds that played baroque-tinged rock and roll. One of the best meldings of classical and rock ever made.
Kak – Psychedelic rock with some great songs.
Siegel-Schwall Band – they have a couple of albums by this name, but I mean the one from 1971 with “Hush Hush” on it. If that song doesn’t get your toes tapping, you’re dead.
White African – Otis Taylor – dark, hard nosed acoustic blues.
Flash and the Pan – their first album by a nose over their second (also great), Lights in the Night. Apocalyptic rock with spoken lyrics. When my wife and I divorced, we fought over who’d get these albums. I won. 
Emitt Rhodes – dubbed at the time “The American Paul McCartney,” since it came out at the same time as McCartney’s first solo album and they both played all the instruments. Great, catchy songwriter you can’t help humming along with. In a just world, this should have been a monster hit; I still can’t figure out why it didn’t spawn any hit singles (back when hit singles could still be great songs).
Song Cycle – Van Dyck Parks – A truly adventurous album; if it had caught on, it would have changed the face of rock music. Alas, it did not.
Third – Soft Machine – a perfect melding of jazz and rock; when it came out, some critics called it the best rock album of all time. Four songs, but each is over 18 minutes long (it was originally a two-record set).
It’s a Beautiful Day – the name of the record and the group. San Francisco psychedelia, one of the few rock groups with a violin as its signature instrument. “White Bird” is a classic song, but the rest of the album is stellar.
Hot Tuna – a spinoff of the Jefferson Airplane with Jack Cassidy and Jorman Kaukonan playing great acoustic blues, joined by Will Scarlett on harmonica. The group was supposed to be named Hot Shit, but the record company got cold feet.
Papa John Creach – Creach was a blues fiddler who came to prominance with Hot Tuna and the Jefferson Airplane after years of toiling in the shadows. His solo album is an eclectic mix of songs, from blues to “Over the Rainbow.”