If you have been in the martial arts for some time, you have definitely run into somebody who claims their martial art is the best.  The Ultimate Fighting Championship is reputed as only have the best martial arts to offer in the cage.  Many instructors profess their system is the best, but in what context?
Let me be blunt; there is no martial art that ranks the best.  If that were true, you could render yourself invincible.  Obviously this is not the case.  Royce Gracie was the reigning champion in the Ultimate Fighting Championship, but is eventually defeated.  Gracie is no joke and neither is his style of fighting, but it does not necessarily make him untouchable.
There are many styles of martial arts in the world today.  From traditional styles to more contemporary like boxing and kickboxing, they all have a mix of strengths and weaknesses.  Eventually, an opponent can learn their opponent’s mistakes and capitalize on them.
However, there are martial artists that rank the best in their field.  Just like Gracie is in Brazilian Jujutsu and Raymond Daniels in point fighting, it is the fighter who gets the style reach its full potential, not the other way around.
One thing the UFC is getting right is the use of mixed martial arts.  They incorporate both striking and ground fighting from a variety of disciplines.  This is advantageous if you want to stay on top.  The fighter who continues to develop his skills based on the ongoing changes in the martial arts realm will be much more prepared in the cage.  Just like everything in life, change is going to happen, and as a martial artist, it is up to you to adapt to ongoing changes.