For me it's ear lobes, collar bones, shoulders when talking about female body.
And for other I'll say things that arouses me most are when a female especially married one wears any necklace and it hangs down to her cleavage getting all squished up between those two luscious melons, when they wear shorts and your thighs and their's touches, their perfume, their naked waist, sitting against their back and feeling their bra straps on my back. These are some things that arouses me the most. Hehe!!