When choosing a language dictionary it is important to bear in mind the reasons for such a choice. Do you need a dictionary for travelling, for studying, or a dictionary to learn the use of the language, or a dictionary of slang? If you belong to Beginners or Intermediate courses a bilingual dictionary would suit you better while a monolingual dictionary would be more appropriate for an Advanced level.
your dictionary, consider if you would prefer to learn Brazilian Portuguese or European Portuguese as some vocabulary and pronunciation can vary enormously (just as English can vary depending upon its origin, for example from Australia or the United States). The best dictionaries should include the items listed below, or at least most of them:
Below is the suggested list of good and affordable pocket dictionaries you may wish to buy. However, be aware of the facilities they offer you according to your priorities. It is not always possible to find the entire list of items suggested above in any one dictionary.
Some of the better dictionaries include:
Another suggested dictionary is the Larousse (NOT a pocket dictionary): Larousse Concise Dictionary Português/Inglês, English/Portuguese. Larousse.