there is ESSURE, which is advertised as a better alternative to tubal ligation. It is inserted the way an IUD is inserted, and in the uterus it sort of blocks off fallopian tubes forever. I have had an IUD inserted thrice, and it is a painless, straightforward outpatient procedure. If ESSURE is indeed that easy to get, then it is better for you than tubal ligation (plus, apparently it is even more effective), but look up complications that patients on ESSURE report.

If I were you, I would simply get a Mirena IUD, since nowadays it is inserted in women who have not given birth (in the past, you needed to have given birth at least once to get it; I got it after my third child who will most likely be the last one for me). Mirena, unlike sterilization, is reversible, and you do not know what you will want and whether ten years from now you will be with your current fiancé. You may by then have separated from him and found another man who would really really want to have children, and you will be able to give him a child. Plus, Mirena is more than 99% effective, so it is on a par with tubal ligation in terms of effectiveness. Plus, Mirena has other benefits - it reduces the blood flow during menstruation (30% of wearers have no periods, and I am in that group) and offers a mild protection against cancer. Tubal ligation does none of that. So Mirena wins over tubal ligation.