I didn't know about the dictionary feature. I like the Google translator, gmail and knols. Those are pretty handy. The only Google "product" I don't like is Chrome.
Google search, Gmail, Google maps, Google earch, Google insights, Google analytics, Google webmaster tool, etc. They are all great services.
Google books... Because I can look through serious sources, the best and newest studies, and use quotes and references and use them in articles without buying or borrowing the books. For "quality content" that is.
Google search, gmail, analytics & webmaster tools(was a bit frustrating at first getting things synced) but still good . I swear the analytics thou would have you compressing the images down to nothing lol