Well for me it depends on the guy. I'm currently attracted to a guy that I met at a bar some months back. At the beginning I wasn't attracted to him straight away, that came with time. But his personality is what did it for me. Now I'm not saying that i didn't think he was good looking, I did. But i found myself noticing more and more about different features. I find now that I really like his eyes, especially when he wears his glasses. Also lips, and shoulders. I love any guy in a nice fitted shirt.
Anyway usually the eyes are what do it for me, and smile. Shoulders and arms are also what I find attractive, But not huge Muscley arms.