I know that this answer will probably recieve oodles of thumbs down, but Oh well, ask me if I care?
I think that the NY Yankees are the greatest team ever, not because of the pennants, not because of the world series championships, but because of the rich tradition to taking chances and the dedication of winning for their fans. Many will argue, and rightly so that they "purchase" championships. I agree, to a certain extent. The outragous salaries that some of these "celebrity" athletes recieve (and this includes all teams) are off the Richter scale in terms of magnitude. Conceiveably, me being an ordinary average person, can not even begin to comprehend 25,000,000 dollars A YEAR! But nonetheless. Getting back to answering your question....
The dedication to winning is what makes them the greatest.
Back in 1920 when the public trust in the sport of baseball was at an all time low due to the Black Sox Scandal, many were turning from America's pasttime, it wasn't until Harry Frazee made the BIGGEST mistake of his life and sold his biggest rival, the New York Yankees the man who would single handedly bring back people into the ball park. We all know him as Babe Ruth. Taking chances and Dedication to winning.
In 1934, a relatively unknown ball player for the San Francisco Seals tore the ligaments in his knee, which should have ended his career, but instead managed to capure a few scouts attention. The Cubs turned him down, and again, the Yankees, dedicated to winning, took a chance, and so cross country, from San Francisco to New York he traveled to become one of the greatest of all times, Joltin' Joe DiMaggio. Again, Taking chances and Dedication to winning.
(Not much different, it is, than the game of life)
I could go on and on, because there are, in my eyes, so many greats, so here is just a brief summary as to why I think and believe that the New York Yankees are the greatest team in sports.