The most effective forms of birth control are the ones that you will use consistently. My patients ask me that all the time, especially when they're starting birth control for the first time. To be honest with you, every form of birth control that we offer in our office is effective.
The hardest part is figuring out which is the best one for you because there are problems if you don't take the birth control. You're not going to have the effectiveness that you would like, and then we'll have a much bigger issue.
Most patients will start with birth control pills because that's the easiest and the one they're most familiar with, but it may not be the best birth control for you. There are many options out there, including condoms which work beautifully, but you have to use them every single time. The hardest part about condom use is that you get no time off for good behavior. In other words, you can have 20 years of compliance, have 1 accident, and show up with a positive pregnancy test.
The birth control options that we offer in the office are very effective. The birth control options that are available in the pharmacy that are effective are condoms, and that's pretty much the only ones available over the counter that I think are effective.
So, in general, if you find the birth control that works for you, that has the minimal amount of side effects, and you're willing to use it consistently, that is the best form of birth control for you.