1984 by George Orwell
Catch-22 Joseph Heller
Dune by Frank Herbert
East of Eden by John Steinbeck
Good Omens by Terry Pratchett and Neil Gaiman
Snow Crash by Neal Stephenson
The Color of Magic by Terry Pratchett
The Lesson by Cadwell Turnbull
The Name of the Wind by Patrick Rothfuss
The Parable of the Sower by Octavia E. Butler
=Less Noteworthy
Black Sea Gods by Brian Braden
Mythos by Stephen Fry
Smallworld by Dominic Green
The One by John Marrs
The Unlikely Pilgrimage of Harold Fry by Rachel Joyce
The colour of magic isn’t highly rated by anyone. Most discworld fans will tell you to skip the first two books and don’t really count them. I hope you didn’t skip discworld based on that. If your willing to give it another go, most fans suggest starting with Guards Guards! as the feel of discworld is well established by this point and the Watch sub series is a fan favourite.
There are 5 main sub series; the Witches, Death, the Watch, Industrial Revolution and Rincewind. Rincewind is the least rated. You can read them in pretty much any order but each sub series is recommended to read in the reading order:
I found the humor in the first several chapters of the first book to be juvenile. The kind of humor you can see coming from a kilometer away so it's just too obvious and not really funny.
Every discworld fan will agree. The first two are terrible. They are straight parodies of the fantasy genre in the 70–80s. The rest of the series are more adult satire of real world issues and institutions and the stories have actual characterisation and pathos.