I stumbled across an extremely large community built multilingual sentence repository: http://tatoeba.org.
It looks like it was designed for language learners with the sentence method in mind, but I am really loving the fact that you can search for sentences with keywords in them to gets multiple different shades of meaning. I also like being able to see a sentence and simultaneously look at its translation in other languages I know. I think having multiple reference languages gives better understanding than having just one.
I think this could be helpful if it was integrated as a dictionary resource option, so it’s only a click away when checking the meaning of a word in the lingq editor.
Tatoeba is a bit different than the ones eugrus mentions in that Tatoeba is all community driven, users add new sentences and add new translations, and approved users modify translations.
Linguee and from what I understand the Examples mode of lingvopro are more “dynamic” in nature, in that they use bots to find manually translated content on the web and use these sentences as the basis for their examples. I also like that Linguee does some post processing as well to sort of combine the dictionary + examples functionality seamlessly, whereas Lingvopro supports a whole heck of a lot more languages. All in all, I think that these three different sources complement each other very nicely.