I'm a Hebrew nut. I love Hebrew. I study Hebrew. The Hebrew Bible/Old Testament is the sphere in which I dwell. So I'll make a few comments based on that sphere...
I don't need an English translation. In fact, I prefer to make my own (I am doing my own translation of the entire Old Testament). I mainly look at other English translations after I have already done my own in order to see what they think the Hebrew says and why they think that.
Although I have not done a great deal of comparative study with other translations of the Old Testament/Hebrew Bible, so far, what I have found is that the New JPS Tanakh, the Stone Edition Tanach, and Robert Alter's translations are closer to the Hebrew and more accurate in their treatment of the Hebrew than any other.
In the Christian stream of translations (which are pretty nasty across the board when it comes to the Hebrew OT--it's as if the Greek NT was the most important thing for almost all English bibles ever created), something I had never heard of before, Green's Literal Translation, has outshone its peers in about three different comparisons I've undertaken with other major Christian translations. Which is not to say it's a good translation. In fact, after reading a Wiki article on it and learning something about it's author, I felt a bit sick. But if it outshines the others in three places, it might in more.
A translation I'm hoping to spend more time with in the future is
ISV.