Google Translate - Google's free service instantly translates words, phrases, and web pages between English and over 100 other languages.
GoldenDict - The program has the following features: Use of WebKit for an accurate articles' representation, complete with all formatting, colors, images and links.
DeepL Translator - DeepL Translator is a machine translator that currently supports 42 language combinations.
Wiktionary - Open Source wiki-dictionary by the Wikimedia foundation
Linguee - English Dictionary and Translation Search with 1,000,000,000 example sentences from human translators. Languages: English, German, French, Spanish, and Portuguese
dict.cc - dict.cc is not only an online dictionary translating from English and German to 21 languages.