I have seen Discworld in stores millions of times and have never felt the urge to read it. May be it's the series name. I grew up with CS Lewis and Roald Dahl and "Discworld" doesn't sound right. May be this is the time to pick one up. RIP.
They are definitely worth a read, though you don't need to read them in sequence - in fact Terry Pratchett suggested you don't start with the first books
Pratchett masterfully used fantasy as a tool to convey satire on our world, to accentuate the quirks of our society, politics, technology, religion. Some of my favourites are Moving Pictures, Small Gods, Soul Music, Hogfather, Going Postal.
His first two novels, as well as Hogfather and Going Postal were adapted into moving pictures, with Sir Terry making cameo appearances in them.
I first heard this song, the intro to the Discworld 2 game, a couple of decades ago, and now it feels as a somehow fitting tribute, maybe the way Terry Pratchett would have wanted people to look at his own going away.
https://www.youtube.com/watch?v=NUrvR0Ig-YA