Babel Fish
From Hitchhiker's Guide to the Galaxy. Of course, this is not a "machine" but rather a living creature. However, Douglas Adams also suggests it could not have evolved naturally. The wikipedia sums up this state of affairs:
"The Babel fish is small, yellow, leech-like, and probably the oddest thing in the universe. It feeds on brain wave energy, absorbing all unconscious frequencies and then excreting telepathically a matrix formed from the conscious frequencies and nerve signals picked up from the speech centres of the brain, the practical upshot of which is that if you stick one in your ear, you can instantly understand anything said to you in any form of language: the speech you hear decodes the brain wave matrix."
It is a universal translator that neatly crosses the language divide between any species. The book points out that the Babel fish could not possibly have developed naturally, and therefore it both proves and disproves the existence of God.
Of course, this seems to fall into the deus ex machina category (or, possibly, the reverse, but I can't remember my Latin cases well enough to recall the proper endings needed to reverse that).
TARDIS
The TARDIS from Doctor Who translates both spoken and written languages into a format the doctor and companions can understand, and also translates what they say into format the people they are interacting with can understood. It is said that this is accomplished by a telepathic link between the TARDIS and the Doctor (plus companions), but I'm not aware of any details beyond that.
There are others listed at wikipedia, but that is definitely not comprehensive, and lists the show Stargate which I believe explicitly didn't have a universal translator. (Almost everyone in the Stargate universe speaks English.)