Well, first off, looking at his Fleetwood Mac career, avoid nothing other than Mr. Wonderful.
From his Splinter Group years, most of it is pretty good although the first album, Peter Green’s Splinter Group is a bit weak. Nevertheless everyone was pretty forgiving about this because it was a miracle he could stand on stage, let alone play.
As for his dark period, I bought all of the following and then gave them to Oxfam; Blue Guitar, Whatcha Gonna Do? White Sky; Colours. Literally tear-inducing, for all the wrong reasons.
As a footnote, PG was a, if not the driving force behind one of the greatest live blues albums ever, Fleetwood Mac Live at The BBC. He was also, just a few months later responsible for one of the most unlistenable albums of all time, the End of the Game. He was, it must be said, seriously mentally unwell at that time. He only performed this album once, live. I was one of the hapless members of a deeply sad audience at a free gig in the garage at a back of a pub in Barnet. But that’s a story for another time, perhaps.