Since they are abou the same on skill level where would you rather play if you were a pro. I would say J-League since they play infront of packed crowds almost every game.
Well I guess it depends on the money and where you would prefer living. Seems like the J-League drops a little more money than MLS does for international players but given the choice between living in Japan and the US. I know exactly where I would want to live.
for your average football player from around the world...hmm...lets see...more money, livelier fans, better television and media coverage, more teams, better and more open play, incentives to place at the top to enter Asian Champions League (i laugh that Concacaf still tries to have a club confederation tournament, when MLS teams don't even want to play in it), brazilians playing there(if you want to beat the best, might as well learn from the best), and last but not least, internet boards with people with less inferiority complexes like here on BS!?!?...J-league in a landslide. p.s. If MLS is still around in ten years, have this poll again, and maybe it will be closer.