Its difficult to say one best tool, all of them have their on ups and downs. So its better to try different tools and use them based on the context/use-case.
Some of the tools which I have already tried:
Out of this sketch+craft, after effects, paper+pencil and principle are the ones which I use on a day-to-day basis.
Just keep following product hunt, people are coming with a hell lot of new tools everyday. Keep an open mind and try those. Keep your focus on what you want to make rather than on tools :)