I was a fan. Regarding the earlier stuff, after PG, then came the Bob Welch/Danny Kirwan era, which I found gratifying.
Excellent comments Marty on Kirwin's contributions to this band. It was a magical time, certainly not having the commercial success of the Nicks/Buckingham period but offering a major contribution to the body of work of this special band from their inception. And time goes by. 
agreed. "then play on" is still blues-derived, tho you can hear them veering into sort of cosmic folk/psychedelia. to me, the next one, "kiln house" is the real transition from the peter green straight blues to their eventual AOR/pop guise--kirwan's "jewel eyed judy" and "tell me" are classics, tho i also dig jeremy spencer's rockabilly stuff.
Terrific songwriter and guitar player.  In some ways, he was the most influential member of Fleetwood Mac, they really broadened their approach from straight up blues when he joined for Then Play On.  Mick Fleetwood credits him for introducing harmony into the band's language.

i gather he was always a difficult personality, but it's still sad to hear news like this.
...and, don’t forget "Kiln House". Kirwan played on that album too which had some rockin’ tunes! :-)
Danny Kirwans "Jigsaw Puzzle Blues" was a Tour De Force equal to Django Reinhardt at his most expressive playing!
I played Sunny Side of Heaven in his honor as soon as I heard the news - great artist - I read somewhere he was homeless and lived in a hostel - so sad
I will be listening to Blues Jam at Chess this late evening and remembering great times had while enjoying his music as a youth, both he and I as we are close in age.
Sad news. Future Games (the album) remains a favorite and, I think, a good memorial to DK.

all celebrities are under attack from different sides and angles and it sucks. looks like Harvey is ready to blow his brains off with 9mm or just chunk of dope.
When you rock, I guess, there's always a woman or few that wants part of you and you're one going crazy-- nothing unusual I guess. Whatcha do in response is put your own brains to sleep so wealth is distributed among your closed ones... 
having vaguely remembered reports of drug or health problems, i actually thought he passed years ago. in any event, he was an understated genius--for my money his iterations of fleetwood mac were by far the strongest, with then play on, kiln house and bare trees being classic records.
So many, so young yet. My heart goes out to his family and the ones he left behind. Sad, so sad. RIP mate.