By the President's Commission. "With a special introduction by Harrison E. Salisbury and other material prepared by The New York Times," for this paperback edition from 1964, which is unabridged. I also enjoy this edition's cover photo, in which Kennedy seems to be pulling a "...really?" face at various theories about his murder.
If you've never read the WR, this is a frumpy but budget-friendly copy — visible shelfwear, nicks and splits to the covers (plus some wag drew a target on Kennedy’s forehead); crunched pages, toning, the works. But it’ll get the job done to read and recycle.