What's the best contraceptive?

Depends: It depends on so many factors that are personal to you. Health factors, life style factors, etc... So the best person to give you good advice is your gyn or see a np at planned parenthood. They will steer you in the right direction.

Varies: Situations influence what choice would be best.If you just look at numbers, abstinence has no risk of conception, followed by an IUD which fails <1%/yr.IUD's have higher initial cost & discomfort but require little upkeep & last for 3+ years. Implantable/patch/pills all work when tolerated.Condoms have a higher failure rate but offer some protection against disease.You get options to choose from

Don't have a clue: The "best" for anyone is whatever is determined after a good medical history, review of present health issues & meds and an understanding of how/why it is being used. An IUD requires little daily thought but is pricy. There are dozens of "pill" choices that may or may not work well with a particular person. In short, you find this out by working with a health professional over several months.