Opposite sex or same sex it really doesn't matter depending on who you are. What makes you the most attracted to the sex of people you date. You can always add on to this list.
http://www.ranker.com/list/what-attracts-you-the-most-to-the-opposite-sex-/stokified,
Tattoos
Glasses
How Unique They Are
How Simlar Someone Is to Yourself
Not Wanting to Be Alone
Personal Habits
How Different Someone Is to Yourself
Lack of Intelligence
Iq
Superior Intelligence