The books are very much worth rereading. The layers of jokes and references are so deep that you likely won't catch all on the first or second reads.
I can recommend The Annotated Pratchett File, https://www.lspace.org/books/apf/, for an in depth review of a lot of jokes and references. It explains a lot of things that are hard to catch if you haven't grown up in England. Many things i thought Pterry had made up for the Disc is just references to real world things and events.
I recently finished the Discworld series by Terry Pratchett. Wonderful books. I read it in order of subseries which is a good way to get into the books, but it does make it a bitt jarring when going back to the first books, before Pterry really found his stride. Once I get around to a reread I think I'll do it chronologically.
As a change of pace i continued with Fear and Loathing in Las Vegas. Something of a whiplash change from Discworld and a it got me a bit too amped when reading right before bed. Still a very fun and interesting read.
Now onto SAS: Rogue Heroes, which i started earlier but have yet to finish.
It's even funnier the second time!
Sadly i've just discovered that from Going Postal and onwards there are no annotations. Seems the project never finished with all the books :/