I'm an only child, so you might be thinking there's no way I could know if sisters are the best. Really, though, I know lots about sisters. I always wanted one growing up, because sisters are often like built in best friends. Plus, as an adult, I've created a really great family of friends and am very lucky to have several women I view as my sisters. I know it's not the same, I know that every sister relationship is different, and I know things aren't always rosy, but that's true of everything. In general, sisters are pretty damn awesome.
1. They're Teachers
Sisters are the best in general, but if you have an older sister, you have a great teacher. Actually, the two of you will teach each other new things your whole lives, especially if you're close. You might not always listen to each other's advice, but you share it and hope that it will someday help.