I've been reading a lot of Wodehouse lately, and while a lot of Wodehouse is incredibly good, some is really best left alone. So far all of them have been adapted from the stage. Of course this cannot be a coincidence, and so far I have a two-fold theory to explain the phenomena:
1. Dramas require a certain kind of slang which does not age well--it has to be the kind of slang used at the time. The rest of Wodehouse's novels are full of slang, too, but it's the slang of the Golden Age (that is, it's never existed).
2. The snappy cross-talk which is so enjoyable in drama does not translate well to the written word. For some reason it's grating rather than enjoyable.
Guy Crouchback told me that there was a Jeeves and Wooster book which is also sub-par, but I've forgotten the name of it. (This might be because he couldn't remember the name when he was telling me, but I don't remember.) And Whiskey doesn't like "Joy in the Morning," but I think it's okay. Also okay but not great is "Leave It to Psmith."
This is the list of Wodehouse books to avoid:
The Small Bachelor (readable)
The Return of Jeeves (not readable)
A Gentleman of Leisure (not sure--slogging through it right now).