Although I prefer large natural breasts, I'll take a natural AA over fakes of any size. Fake boobs can look great in clothing and in some swimsuits, but they all look bad when the woman is naked. Every set of fakes boobs I've ever seen looks fake, and certainly they don't move like the real thing. I've had some hands-on experience with implants, and yes I did enjoy palying with them, but I enjoy natural boobs much more.
The only exceptions to the fake looking fake rule (and they are very rare) are women that had something substantial to start with, and had small implants to fill their breasts out, or to compensate for some sagging.
I think a good example of this is Catherine Bell (used to be on TV show JAG)
She was always a busty woman, but she got into great shape and her breasts were not as firm as they used to be (see some of the movies and HBO shows she did before she became well know through JAG.) If you see her pictures from FHM or Maxim or whatever, she looks outstanding.
Of course, reconstructive surgery due to cancer, other illnesses, or any medical condition can give a woman some of her confidence back.
I think the only natural method that works is getting pregnant, and that effect can be temporary.