With guys, it's dicks and legs. If a guy has hot legs, especially nice calves....mmmmm, my mouth begins to water. Eyes and lips do it for me, too.
With girls, booties and lips. Nothing turns me on more on a female than a lovely, firm ass; makes my whole 9 inches swell to full erection :biggrin1:. Lucious lips are sexy as well. And eyes, but I think eyes are pretty universal, ya know?