There's only one Discworld book I don't like, and it is unseen academicals - the football one - I struggled to finish that, and it's the only one I've read only a single time. Every other discworld book I've read numerous times over the past 20+ years.
The one thing I'll fault the Moist books on is they're sort of the same book 3 times if you're in it for the story. If you enjoy the post/finance/rail exploration, that's enough to get past it, and I certainly did, but I can't blame others who didn't.
For eg., Going Postal and Making Money have the same basic setup, and a one-line story description would sound very similar. But Going Postal is about themes of past and future, regret and risk, connecting to the past while bringing in the future; while Making Money feels like a constant tug-of-war between order and chaos, and hence ultimately about balance.
There's a point where you get a lot of rather similar monologues from his characters. I presume these are from the period after he had to dictate as he couldn't write directly any more. If so it's amazing that they're as good as they are.
What an embuggerance (as he said himself).