In reply to RockAngel:
BRIAN BLESSED!
Good for old Land Rovers and other noisy vehicles. You could probably still hear him from inside a motorbike tank bag with a full-face helmet on. ;O)
I used to have an Ozzy Ozbourne voice on my sat nav (or a fairly convincing impersonation, I guess it probably wasn't really him). I actually quite liked it that he sounded a bit vague and unsure of himself - it was a useful reminder that the sat nav directions are just a suggestion and you can ignore them if you like.