I myself prefer the boatneck, as it tends to make your neck look more slender. Of course, I also have a small chest, so really any shirt works for me. If you hate your collar bone, a jewel neckline works well to hid it, as can a boatneck. Larger chest? V-neck t-shirts can help keep your chest from ka-powing it in a t-shirt. I usually prefer to wear my hair down when I wear a v-neck, or a more scooped jewel neck line (the polka dot shirt.) I also prefer to not wear a jewel neckline (the orange tee) with a jacket or blazer, because it creates a disproportionate line that is not in harmony with the cut of the lapels - more on that tomorrow!
I can't end this post without mentioning turtlenecks, my second most favorite neckline - for hiding my neck and framing my face at the same time.
I also can't end this post without mentioning the importance of the right bra. Bras should hold your ladies in the front and center - if you find them going in any other direction, your bra might not be giving you enough support. Most stores have an associate available (and trained) in measuring you for your correct bra size.
And while we are on the topic of bras and breasts - don't forget to schedule that annual appointment with your doctor! Early detection of breast cancer = 93% chance of survival (not the survival of your breasts, but the survival of your life.)