Mustang, not exactly sure what is being measured (total team revenue?, income?, is TV revenue included?) but it is in interesting list and it shows the incredible $ power of North American team sports. It also reflects the tremendous purchasing power Americans (ok, a handful of Canadians as well) posses and their willingness to support their professional teams, all fine attributes in my book.
But it does not answer the initial question as the "biggest" sport which is clearly soccer (futbol for purists like me) with 207 FIFA recognized national teams. It's a staggering figure.