I think a lot of picking all time first eleven depends on what basis you pick your player from. Obviously there are certain great players who have played for Juve but not quite made the impact because (1) they were too young or (2) their career was on the downside. Moreover, I think it is only right to honour those players who has given long time of service to the club than having one or two unbelievable years. This means that likes of Alex, and a lot of stars in the 70s and 80s should be favored over current crop of players, when in the era of quick turnover of players 5-6years seem almost an eternity.
Also, it helps if the player not only played some oustanding football but also can personify the team in terms of off the pitch activities, and integrity they represent. This means IMO likes of John Charles should be given priority over perhaps reputedly more talented but volatile Omar Sivori.
With this in mind
My all-time eleven is on paper,
Zoff - Ferrara, Scirea, Gentile, Cabrini - Tardelli, Deschamp - Zizou, Platini Bonipierti - Del Piero
Sub: Charles, Baggio, Montero, Causio/Nedved, Pessetto, Cuccerreddu (Can't spell his name

), Peruzzi
Coach: Lippi
Based on the players that I have seen
Peruzzi - Ferrara, Montero, Kohler, Pessetto - Deschamp, Davids - Baggio, Zizou, Del Piero - Vialli
Sub: Nedved, Buffon, Jugovic, Trezeguet, Thuram, Conte, Torricelli (On his good day).