Alas, The Old Man and the Sea goes unchallenged as my favourite Hemingway.
While Farewell has some exceptional excerpts, most of them about war and how soldiers feel towards it, Hemingway can't write romance. I feel it's because he can't write a creditable woman (except maybe Pilar from For Whom the Bell Tolls, though he compensates with the wet dream that is María. Maybe it should be that he can't write a strong love interest?). Most of Catherine's lines sounded so trite they made me cringe.
Paring all the tragic saccharine, we are left with quite a piece of it's time, so I reckon it's worth the time if you have it.