Buf, that’s really difficult. I’ve been lucky to see some great players. Would be harder if I did it for Arsenal tbh.
Alves-Piqué-Puyol-Marcelo
Diaby/Alonso/Kroos/Pirlo/Busquets-Xavi-Zidane (honestly have no idea how to pick a midfield 3 out of all those players)
Iniesta-Messi-Ronaldo (gay)
honourable mention: Neymar, Ronaldinho, Cesc, Ronaldo, Modric, Bergkamp, Özil, Overmars, Villa, van Persie, Falcao, Torres, Agüero, Forlán, di María, Cazorla, Eto’o, Robinho, Seedorf, Davids…surely forgetting a lot. (edit: Hierro, Suárez, Robben, Sneijder…)
And not even including players who I saw in the mid 90s when I was younger and couldn’t appreciate as much. One of my great regrets is never seeing Ronaldo live before he got injured/fat and never seeing Henry in London.
Edit: forgot about Riquelme
That midfield is honestly impossible. And Figo but never really liked him haha guess it’s probably because he’s both a Barca and Madrid cunt, especially the latter.
Love these threads that get me all nostalgic and get my memory working about football. 
@SRCJJ de Rossi in your XI that’s poverty m8, surely you’ve seen better