What would you say is the best Spanish-English dictionary and why?

I'm a Spanish student, and I'm looking into buying a new Spanish-English (or English-Spanish, if you will) dictionary. My professor recommended one that he things is really helpful, but I'm open to other suggestions, especially if you can explain why it's the best to you! Thanks!What would you say is the best Spanish-English dictionary and why?
I would really recommend the Harpercollins Spanish Unabridged Dictionary . It's one of the most complete ones that I've seen because it has all the words that mean the same but that are said/written in a diferent way according to the country they are used in. Many dictionaries have only one side of it, for example spanish from Spain or spanish from Mexico.



But this one has words from all of Latin America.



Hope it helps!What would you say is the best Spanish-English dictionary and why?
The best choices by far are Oxford, Collins and Larousse. These dictionaries do not simply list translations, but they give good information to guide users through the semantic and syntactic complexities. They maintain an up-to date lexicon and give slang translations.

Larousse is a good choice.What would you say is the best Spanish-English dictionary and why?
you might want to try http://m.askvelazquez.com

it's a 250,000 word Spanish-English English-Spanish dictionary made for the iphone web browser. The company is also going to come out with a downloadable app soon.