Itachi vs Minato...
I would say Minato but It could go one way or the other. Itachi ultimate weapon, susanoo, would not work against Minato because it has a weak point at his back.
Minato ultimate strength is being able to exploit every weakness with his speed, no matter how small. I doubt that is the only thing he can do. Can he for example go into sage mode? So far he only needs two moves to take out enemies because it works so well.
Itachi is still not to be underastemated, he has far more then Susanoo. He has black flames, and Tsukuyomi, powerful genjustus and is frightenly strong, most likely the strongest of the akatsuki and might have been able to take out Raikage more often then Rakigae would be able to take out itachi.
If Minato is able to get his knives or markings into blind spots, then he will control the battle. If not, then Itachi will might win.
Minato most fearsome technigue is not really being able to teleport himself, but to be able to teleport any object.
Any powerful technigue like amaterasu could be teleported away.
If Itachi strikes Minato with susanoo with the sword of Totsuga, then Minato could teleport the attacker in area where he has his markings on all critical locations.
Itachi could use Tsukuyomi to gain advantage, but that would strain his eyes and is easy for Minato to avoid with use of clones(and without).