What's the best agile framework?
Hah! We're not getting drawn into this one...
Seriously though, the reason we laugh is because for some people, the debate around the pros and cons of the different agile frameworks out there becomes something like a fanatical war, with their side being right, and the other side being the enemy. So I'm afraid we can't answer this question specifically.
In our opinion, all the frameworks out there have their value in certain contexts. None of them was invented by people with bad intentions, and all of them have their own fans for their own very good reasons. If you want more on this topic, you could take a look at the Agnostic Agile Oath, which includes the statement "I will not be dogmatic when it comes to lean or agile frameworks or methods, because dogmatism is non-agile, does not benefit my customer, my community or lend itself to continuously improving my own practice". We tend to agree.
Rather than talking about the 'best' framework, if you wanted to talk instead about which are the most popular or widely used frameworks, then you could look at the VersionOne 'State of Agile Survey' which comes out every year, and reports on which frameworks people are using the most in the last year.
Perhaps though, the only answer to this question is to say that the best agile framework is the one that works best for you and your organisation.