OrbWeaver
BECAUSE FALCONER
That one was kinda like an 'on the side' Discworld book. I'm not sure I've ever read it. Now I'm not sure I want to bother.
With Feet of Clay, I always thought I wasn't quite 'getting' something. Since it focuses on golems, I might not be familiar enough with the concept.
If you are a Rincewind fan, then you should read Eric, just to kind of keep up on where Rincewind has been. That character has been through ALOT thanks to Pratchett. Also, it's sort of a Faust spoof.
As for Feet of Clay, if you're somewhat familiar with mythology surrounding golems, it should be fairly easy to get. A Golem is basically brought to life by putting a spell inside the construct's head, with words that outline the task the golem is supposed to do. So the Golem that went batty basically had too many words in its head.
There, I think I explained that without giving away any spoilers for potential readers...