Live it would be Messi by an absolute mile, and I've seen Cristiano Ronaldo, Ronaldinho, Zidane, Figo, Xavi, Iniesta, Del Piero and most of the big names in the Premier league who the boro have played against.
Not trying to be facetious....Terry Cochrane, Stephen Bell or Stan Cummins.... 30 years before Juninho but had that flash of genius...amoungts the grey.
Suppose it depends on what you mean ..by reputation,by individual performance or who took things to another level on a cold drab and misrable Saturday afternoon.