OK, the one that always makes my knees weak (but only when DH is wearing it!) is
Obession for men by Calvin Klein. That was one of his original scents when we first started dating. Just the scent of it brings back memories
He is currently wearing
Polo Blue for men, I got him a gift set with the cologne and a deodorant stick... and the deodorant stick alone is enough fragance all by itself. It's pretty light, airy and clean smelling.
One of my other favorites on him is
Armani Code or
Very Sexy 2 by Victoria's Secret.