Have always loved Robert Browning. In addition to the chilling narrative voice of "My Last Duchess," a couple of my other favorites are Fra Lippo Lippi:
It makes me mad to see what men shall do
And we in our graves! This world’s no blot for us,
Nor blank; it means intensely, and means good:
To find its meaning is my meat and drink.
or Andrea del Sarto:
Know what I do, am unmoved by men's blame
Or their praise either. Somebody remarks
Morello's outline there is wrongly traced,
His hue mistaken; what of that? or else,
Rightly traced and well ordered; what of that?
Speak as they please, what does the mountain care?
Ah, but a man's reach should exceed his grasp,
Or what's a heaven for?