"And then, after walking all day through a golden haze of humid warmth that gathered about him like fine wet fleece, Valentine came to a great ridge of outcropping white stone overlooking the city of Pidruid."
-- Robert Silverbert, Lord Valentine's Castle
This opening line is rich with imagery and sensation, a dreamlike intensity fully appropriate for a novel in which dreams figure so prominently. Lord Valentine's Castle is one of my favorite books of all time, a book I have read many times over and found that it still retains its wonder every time.
In my own case, I'll probably never be able to surpass:
"Dear God, I'm going to die," said Joe Buckley.
Of course, you have to have read the right Baen books beforehand to fully appreciate that line.