HarperCollins Spanish Unabridged Dictionary, 8th Edition ... (ISBN 0060748966)

C.Collins Spanish Dictionary:
This is the single most useful tool that I own when it comes to Spanish composition. Anyone interested in improving their written skills and/or vocabulary in Spanish should have a copy!!

very valuable:
I think this dictionary is terrific. I can't compare it to its other unabridged competitors because I haven't used them. Some reviewers do, so I refer you to them. The greatest virtue of the dictionary, for me, is that it often provides very extensive examples of informal and semi-idiomatic English usage that don't translate one-to-one into Spanish, and vice-versa. This is especially important to me as my tendency, given my background and current career, is always to assume and try for literal translation, which in many cases is either outright incorrect or extremely awkward in capturing the sense in Spanish. In my intermediate Spanish classes we are frequently given short selections by contemporary writers to translate. Though the English appears simple and straight forward, the selections have shifting tenses, many modalities, and informal usage that seems so natural--it's how we speak, after all--but don't lend themselves to easy translation. But almost always I've found a translation short phrase in the many examples of usage the dictionary often provides. Similarly for the contemporary Latin American literature by known authors with considerable idiomatic usage, and sometimes groserías, that we've been given. Of course, the dictionary has occasional lacks and on rare occasion I've found other sources with more choices, such as the wordreference site (which can also have much more extensive discussion in the forums). But this has been true of every dictionary I've ever used. The dictionary's sections on usage, suffixes, etc., I've also found valuable. And, lastly but very important to me because it lends itself to my actually using it, it opens flat. I keep it on a stool so opened near my desk. Some reviewers have mentioned that it favors British English over American. I don't find this very noticeable nor intrusive on the infrequent occasions I notice it--and I consider myself sensitive to this, having a degree in analytical philosophy. Actually, I find it an informative bonus.

Useful, but too heavy:
I own three Spanish dictionaries -- the American Heritage dictionary (2nd edition), Diccionario práctico del estudiante (published by Santillana), and this large Collins dictionary. The American Heritage dictionary is my mainstay because (1) I am usually able to find a clear definition for the Spanish word I want to decipher and because (2) the book is easy to handle. I use Santillana's Diccionario when I want examples of usage. I consult the large Collins dictionary when I can't find what I want in the American Heritage dictionary. I would love to see Collins split their book into two separate volumes -- each small enough to handle easily. I would probably then dispense altogether with my American Heritage dictionary. The English-Spanish volume of the Collins dictionary would be available on the shelf, while the Spanish-English volume would be at my side all the time.

Comprehensive Dictionary:
Half of this dictionary is packed with spanish words, definitions and usage examples . The other half is a very comprehensive english equivalent. Unfortunately, the text is quite small and the book is very big and heavy. Some of spanish words which are derivatives of a ROOT word can be difficult to locate quickly because you have to look up the root word in order to find definition or usage . In the center of the book is a nice section, full of common spanish phrases which I love. This is a very complete spanish/english dictionary.

A Great Dictionary:
Some reviewers have complained about the Britishisms used in this dictionary, especially when they're not labeled as such. It doesn't bother me much. I'm an American, so having a dictionary with a British slant is kind of like having a dictionary with a bonus language.