Jane Hart at the Centre For Learning and Perfomance Technologies has done a great job eliciting people’s favorite online learning tools.
I’ve just updated My Top Ten Tools For Learning. You might find them useful/interesting.
You can also access everybody’s else’s lists and a complete compilation from that same page.
In additino, you can contribute your own recommendations here. If you teach English Language Learners and contribute your list there, let me know and I’ll also write a post about it.