"Best" is relative.
To me, the MetaWatch is the best, because it does exactly what I need it to without being a distraction and it has great battery life. Others will feel it's limited to the point where it's totally unnecessary and instead want an iWatch.
So take a few minutes, think about what you need and what you want, write down pros and cons of all watches available to you, then simply choose the one that's best for you.