My favorite Mishima book is probably The Sailor Who Fell from Grace with the Sea
, largely on the strength of its title. It's evocative, ominous, lyrical and suggestive -- traits that, now that I think of it, fairly describe the novel itself.
The Japanese title, while it isn't bad, isn't anywhere near as flashy. It's 『午後の曳航』 -- that last refers to tugging a ship, as you would do when entering or leaving a harbor. The part that doesn't translate is that it's a homophone for "glory" -- 栄光 -- and thus it neatly summarizes the essential conflict in the book, between a sailor's pursuit of an ordinary life and the boys who want to transfigure him into an idealized wanderer. He's dragged against his will -- dragged to glory, as the pun would have it.
It really is untranslatable, particularly in the constraints of a title. I might have foregone the pun entirely and substituted an allusion -- "Glory in the Afternoon," riffing off Hemingway, or perhaps "Slouching towards Glory" after Keats, both of these reinforcing the link between death and glory, but I wouldn't have gotten anything like Mishima's English title. Truly amazing.