I have read many of the discworld books, including Going Postal, Making Money, Thief of Time, (as well as others), and am currently in the middle of Unseen Academicals. Characters that I like include Lord Vetinari, DEATH (AND SUSAN STO HELIT), von Lipwig (its nice to get a second chance), and Detrius (Strong but knows his limitations.
Favourite book? At this point Thief of Time (death by chocolate!), but I haven’t read all of them yet.