A film version of The Tempest, directed by Julie Taymor and
starring Helen Mirren as Prospero, was released in 2010 and is now
available in DVD form. It is a visually exciting film and also
makes the story reasonably comprehensible.
There have of course been film and TV versions of the Tempest
going back to 1908 (The 1908 film is quite fun, using the
relatively new use of stop action and other camera tricks to
portray Ariel's magic). And the story has resulted in a lot of
off-the-wall adaptations, some using Shakespeare's language and
some abandoning it altogether.