I was pootling about the internets, as you do, looking for decent sonnets written after 1700 [as you do - Ed.], and I found Edna St. Vincent Millay. Why did no one tell me about Edna St. Vincent Millay before?
I like this one in particular. The sestet is haunting me.
What lips my lips have kissed, and where, and why,
I have forgotten, and what arms have lain
Under my head till morning; but the rain
Is full of ghosts tonight, that tap and sigh
Upon the glass and listen for reply,
And in my heart there stirs a quiet pain
For unremembered lads that not again
Will turn to me at midnight with a cry.
Thus in winter stands the lonely tree,
Nor knows what birds have vanished one by one,
Yet knows its boughs more silent than before:
I cannot say what loves have come and gone,
I only know that summer sang in me
A little while, that in me sings no more.