Brian Blessed as Lear seems to ring alarm bells, but if you can set aside the bunptious, not-so-subtle nature of his performance, you get to to see how interesting it really is. Traditional actors like Olivier might put in a sublime and consumate performance, but Blessed has an bold and fleshed out appeal. I think Hildegard Neil as Fool has to be considered one of the most interesting choices for this role. She gives it an edge and level of cleverness which is not always so apparent.
The other performers contribute succesfully too. i think however, regardless of what I say, Brian Blessed's 'King Lear' is an essential part of any decent Shakespeare DVD library.