They were all important, and personally my favorite Star Wars novels by far. :no2: Sorry Rendezvous.
And nah, I read really all the pre-TPM books, a nice amount of the PT/OT books, and Thrawn/LotF/FotJ of the NJO.
Plus, I own every SW book really ever published, so I can always skim through a book at any time if needed, tbh.