Discworld

So, I've finished the Discworld books about the Ankh-Morpork City Watch (according to this reading guide). I listened to them all on audiobook over the last few months. I liked them quite a lot, but I don't know if I want to start on another series or not. I chose the Watch series because a long time ago my friend Chris told me that was the best series, so that's what I read. So now what? Do I start a new series? And if so, which do I go with next?