Clarify what exactly you mean when you say it is “by far the best”. In what specific ways do you say it is “best” compared to all other religions?
Within Buddhism, there are three levels of practitioner.
Practitioners of Initial Scope hope to improve their lot in this and future rebirths through the practice of the fundamental Hinayana teachings that Buddha Shakyamuni taught to all comers 2500 years ago. Though such practitioners may suffer less, they are still reborn into suffering in the endless cycle of rebirths.
Practitioners of Intermediate Scope have a broader goal. They practice the Hinayana teachings as well, but with a greater aspiration: to attain Nirvana, permanently free from suffering in endless uncontrolled rebirths.
Practitioners of Great Scope follow the Mahayana teachings that Buddha gave to some of his advanced students, and which surfaced more generally over the next thousand years as people became ready for them in cultures ripened by the Hinayana. The Mahayana teaches a more profoundly liberating understanding of reality, and also sets the aspiration of the practitioner beyond personal liberation from suffering. The aspiration is not solitary Nirvana, but to become a Bodhisattva, one who has renounced their own liberation from suffering until they have helped to save everyone else first. Standing at the door to Enlightenment, they vow not to go through it until every other being is first saved, and they work tirelessly towards that goal.
The Buddhism of Tibet is Mahayana Buddhism, but also mixed with Buddhist Tantric practices that came from the great monasteries of northern India in the second half of the first millennium AD. A Bodhisattva aspires to help others, but they can really only do so much because they lack the wisdom and power of an actual Buddha. A Bodhisattva, after eons of Mahayana practices, can become a Buddha, and thereby more definitively end the suffering of others, but some people are more strongly motivated to end others’ suffering as quickly as possible, not after eons. To fulfill this aspiration, they practice the incredibly powerful Vajrayana, harnessing the most powerful energies humans have at their disposal, and transforming the power of these energies through Tantric practices. Using such fuel and technology, many attain Buddhahood within a lifetime or two.
For most people who practice a religion at all, their aspirations rarely venture beyond the Hinayana scope at best. Hindus sometimes use Tantric techniques, but at best this is usually in a quest for personal liberation only. Christianity, with the exception of a few of the saints, goes no further (sorry, folks) than a type of Buddhism called Pure Land Buddhism (using deeds and faith to get oneself into a Heaven overseen by a Buddha). This is a branch, supposedly, of Mahayana Buddhism, but with only a rather weak nod to the Mahayana goal of becoming a Bodhisattva oneself.
Within the four sects of Tibetan Buddhism - all of which still beat everything else hands down - I believe the Gelugpa to be the best. It is a reform movement with an emphasis on virtuous behavior, such that it retains the power of the best practices of the other sects, while avoiding questionable practices and attitudes (which have occurred historically) that might bring dishonor upon Buddhism, especially in the modern world.