There are few more epic then Cleese. And Attenborough is one.
Michael Caine. Barbabra Winsor. Couple of others. Oh, and Brian Blessed. Because his voice rocks!
Not as epic, but also cool, would be Trevor Mcdonald.
EDIT: And top the whole Lot. Caine and all. Fable 4 needs Hugh Laurie. Reaver...