Which football league its going to be better NFL, CFL, AAF or XFL?

Most and especially in the USA continue to favor the NFL out of habit if nothing else. 

I personally would rather watch CFL, it's rather grassroots & often more entertaining. 

The NFL is better plain and simple.If any of these other leagues got anybody that stood out above the rest they would be getting a NFL tryout.The leagues you mention don't pay anywhere near what a NFL benchwarmer gets.

NFL with no doubt

the premier league is the home of football

I think the XFL is the best

nfl by far. ...

NFL - others have been, are and will continue to be compared vs. the NFL

AAF doesn't exist anymore.  Otherwise, you need to define 'better'.  NFL without a doubt has the top talent and will continue to do so for decades and decades (at least).  If by 'better' you mean fun to watch or something else, then you'd need to define that.

Look, I hope the XFL succeeds because I'm a big believer that the lack of a decent minor league REALLY hurts the NFL.  But that's all the XFL is or ever will be, and it's unlikely to last very long.

I prefer the NFL, the CFL is not too bad to watch, I will have to watch a bit more of the XFL before I can comment on it, and I did not watch the AAF.