Which are the first five?
From what I understand there's a few main series within Discworld, Rincewind's books, Death's, some about some witches, and the ones about the Night Watch. From what I understand all of them are pretty different tonally? And you can jump back and forth between series no problem (you might miss some small references to other series) but each series does need to be read in order?
It's kind of overwhelming, there's so many books. Also kind of weird that he didn't name the book more accurately, for example Mort could be subtitled "Death Book 1" and whatever book comes after Color of Magic could be subtitled "Rincewind Book 2" and it'd be a lot less confusing.
The Colour of Magic, The Light Fantastic (direct sequel to The Colour of Magic), Equal Rites (first appearance of Granny Weatherwax so it's all right), Mort (fantastic), and Sourcery (ehhhhhhhh) are the first five.
Never been fond of the Rincewind books overall. The Lost Continent is entertaining because it lampoons Australia. But other than that eh. And yeah, you can jump between sub series with minimal problems except you might miss out on some jokes/references. I've read through about 32 total and it was totally worth it just to see the recurring jokes.
The best books in the series are the Lancre coven books.
Wyrd Sisters
Witches Abroad
Lords and Ladies
Maskerade
Carpe Jugulum
Granny Weatherwax, Nanny Ogg, and Magrat Garlick play off each other beautifully. All the books in this sub series are hilarious as well as being fairly insightful.
Then you have the Tiffany Aching books which sort of tie in to the Lancre coven books.
The Wee Free Men
A Hat Full of Sky
Wintersmith
I Shall Wear Midnight
They're great for featuring the Lancre witches as well as having a young protagonist who isn't insufferable.
Then the city watch books are also top notch.
Guards! Guards!
Men at Arms
Feet of Clay
Jingo
The Fifth Elephant
Night Watch
Thud!
Snuff
Again they're funny with a good cast of characters who play off each other well, and they really make you think.
And finally the Death books.
Mort
Reaper Man
Soul Music
Hogfather
Thief of Time
They're the most fun of the lot I think. As well as being the ones that give you the most to contemplate.
All the rest (barring the Rincewind books which aren't really all that) are basically one offs that can stand alone and while good they do not measure up to these four sub series.