Which treatment works the best and fastest for vaginal atrophy?

Vaginal estrogen. My favorite product is vagifem vaginal tablets. They dissolve in the vagina and are not as messy as vaginal creams. Vagifem causes almost no absorption of estrogen into the blood, so it is very safe. Atrophy takes time to improve, however. It will be a few weeks before you start noticing improvement.
Topical. Topical estrogen cream is usually a good option, but check with your doctor about the risks, benefits, and other options.
Laser! I can say, without reservation, that 100% of the patients in my practice who have used a laser device for vulvo vaginal atrophy have had complete resolution of their dryness within the prescribed treatment time frame of 3 months. Additionally, stress incontinence and overactive bladder issues are consistently relieved. Maintenance can be achieved with vaginal estrogen.