I use ABBY Lingvo (a desktop edition for 20 languages), it's my favorite dictionary.
They have an online service which is pretty good, though some features (for example, explanatory dictionaries) are not free:
http://www.lingvo.ua/ru/Translate/ru-en/крошка
Don't forget to try links "Примеры" (Examples) and "Словосочетания" (Set expressions) under the search for every word.