Princeton is a slow outside focused offense with some peculiarities. You can think of it as the outside focused, slower version of Inside Iso. Basically, you want good passing and jumpshooting Big Men and good three-point shooting perimeter players. The offense starts by the PG passing the ball to the C in the high key. The C then either gets a JS or has the offense collapse on him, in which case he kicks the ball out. Alternatively, the ball is passed from the Guard to a Wing player, who drives to the basket for an easy layup. Very good ball movement and good jump-shooting (both C and PF will settle for about twice as many JS as in other offenses, and the perimeter players will get more 3s) are absolutely necessary.
I would say that Princeton is the hardest offense for a team to master, as every player has to fit the system and be very balanced, but it might very well be the most dangerous one if a team is able to execute it. Recently, inthe NBA , Princeton has been played by the Houston Rockets.