There is no best - only ideal for your situation.

You've not given much detail.

Do you want to automatically repost and curate or do you want to make every post you publish?

For our company https://doxflowy.com - we use Hootsuite and we don't publish all the time.

For others, Buffer may be a better option.

Just go with a cheap tool that has a UI you like. They're all more or less the same these days.