Umm...this is gonna make me sound like some weird freak, but what the hey.....
The first place that draws my attention if I see someone front on is the eyebrows. I'm a big eyebrow person, I despise plucked or shaped eyebrows on a guy. If I had to make the choice, I would prefer that a guy have a monobrow than artificial eyebrows.
If I see someone on a profile first of all, I always notice their chin or lack of. If someone has a really defined chin and jaw, it's usually a great indication that they're gonna be toned under their clothes...