Latin Crosswords, by Peter Jones and David Dare-Plumpton
My husband picked this up for me a few days ago and it has consumed every minute of my leisure time since. I'm somewhat of a puzzle buff, appreciating brain twisters of all kinds, and nothing has ever tickled all parts of my cerebrum so delightfully. The cleverness of the authors is astounding. The clues are packed with puns, anagrams, and jokes ("Down from a bottomless goddess" = "de", from "dea") that will gratify any cruciverbalist. Puzzles increase in difficulty; the first section (Facillimum) is accessible to anyone with knowledge of the most common Latin words, but I suspect my abilities---the equivalent of about three years of college Latin, much of it forgotten---will not carry me through the final Difficillimum.
The one imperfection, alas, is that many of the clues make use of incorrect Roman numerals. Rules governing the formation of Roman numerals state that only powers of ten may be subtracted (VL is invalid), and that a letter may not be subtracted from another letter representing a quantity more than ten times greater (IC cannot be written for 99; it's XCIX). It bugs me a bit that the authors don't seem to know this, but I'm willing to ignore it given the absolute genius of the rest of the book.
Note to hubby: do not give your wife a book this entertaining on the first day of her job search. I promise I'll send out some more résumés tomorrow. But it's 3 a.m. and I have some crosswords to do.