Plenty of documentaries I've seen him say without a doubt hes the best.
@Arbitrium point is there is no absolute best and we all have opinions. Based on what you value in the game more you'll have your own best player.
This is what a lot of messi fans just cant comprehend. Some think Ronaldo Brazil was the best. Some thing Cristiano. Some say Maradona and it goes on.
I just have a suspicious the staunch "Messi or bust" supporter does not value anything other than pure ability with ball at your feet.
If you think Messi is the best you're not wrong. If I think Cristiano is the best I'm not wrong. This is football we all see it from different perspectives. If you're just gonna try and place an undisputed leader well you're gonna be frustrated (or at least not have that leader bottle 1000 chances to win an international trophy
)