I hafta go with 'The Whole Package', whether it be her full round tits, her irritated hole, his shaft going in and out.. or the look on her face to see if it's real pleasure or no.
Dude, you should have made this a multiple choice poll with at least 10 options. I look at all the above with regards to the girl and her blowjob technique, whether she's completely naked, her feet, her ass, what she says, her energy level...