Equal Rites by Terry Pratchett (Victor Gollancz, 1987); audiobook read by Celia Imrie (Isis, 1995) Not the most substantial of storylines, yet a key work in the development of the Discworld. Pratchett sets Rincewind aside in favour of the far richer character Granny Weatherwax. In so doing he makes societal change a serious part of his worldbuilding.
Wyrd Sisters by Terry Pratchett (Victor Gollancz, 1988); audiobook read by Celia Imrie (Isis, 1996) Terry Pratchett tells comic stories within stories within Shakespearian tragedy as the King of Lancre is murdered and Granny Weatherwax and her fellow witches take centre stage in the unfolding history of his succession. Celia Imrie does a wonderfully witchy job narrating.
The Shepherd’s Crown by Terry Pratchett (Harper, 2015) Apposite to Terry Pratchett’s passing, his final novel sees the death of Granny Weatherwax (one of the first-introduced Discworld characters) and the befalling of her legacy to young witch Tiffany Aching (one who most embodies the series’ growth): a gentle, bittersweet finale.