"That's my last Duchess painted on the wall, looking as if she were alive."
Opening lines don't come much better than that, do they? Most novelists would submit to torture for it. The questions tumble over themselves - who is the Duke speaking to? why is he showing his guest this rather morbid depiction? why is she not alive? What's he up to? In the next fifty four rhyming couplets, he manages not to answer any of these directly - the Duke is, you infer, playing a deep game here - but by the end, by God, this warped personage has revealed far more than he intended of himself, and you wind up thinking: 'No, Count's emissary! Don't let his daughter do it!'
Browning has been classified as the master, not to say inventor, of the 'dramatic monologue', and certainly his yarns rattle along. (Read him on rats in the Pied Piper of Hamelin.) But there's a lot more to him than just that, obviously. A couple more opening lines:
"My first thought was, he lied in every word, that hoary cripple ..." (Childe Roland to the Dark Tower Came)
"I am poor brother Lippo, by your leave! You need not clap your torches to my face." (Fra Lippo Lippi)
Characterisation! In those few words, you already know a lot about the person: in the first case a driven obsessive on an increasingly surreal quest, against all odds and advice, for an ill-defined and probably futile goal; and in the second a devious, querulous artist whose aim it is to subvert the medieval doctrine that art must depict the spiritual, not the physical - and thereby spark the revolution in thought that was the Renaissance and so most of what came after ...
But perhaps most importantly, he paints in words. At its best, you can almost read this stuff with your eyes closed. Listen:
"All that I know of a certain star is, it can throw (like the angled spar) now a dart of red, now a dart of blue;"
And finally, of course, he's funny, sometimes self-deprecatingly - the next line of that is "Till my friends have said they would fain see, too, my star that dartles the red and the blue!"
Gosh, that was a fan letter wasn't it?