I absolutely adore the discworld books. I've reread many of them several times over the years, they are without doubt a significant contributor to both my world view, and my vocabulary. I can't wait to raise my children with them.

I typically recommend either Small Gods, Wyrd Sisters, Pyramids or Mort as an entry into the discworld. There are so many good start points though.

I can never decide whether to recommend reading a specific character arc, or to read them in publishing or chronological order. I've enjoyed re-reading character arcs a lot though.