What is the top most used PLC systems around the world?

Seimens  and Allen Bradley

Siemens S7 and also Allen-Bradly

I think Allen Bradley and Siemens plc's are used in almost in all industries

Siemens, Schneider, ABB and Allen Bradly are the moste popular and the moste used all over the world.

I think that Siemens S7-300 is a number one and we find schneider PL7 and Mitsubishi .  We cannot forget the new PLc Technology the beckhoff automation-Pc.

I think it is Siemens S7-300

SIEMENS, ALLEN-BRADELY are most adavanced plc system.

this related to application :

1- High Performance CPU / High Price  : B&R PLC  application ( Robotics ) . 

2- Medium Performance CPU / Medium Price : Siemens Family ( S7300 , 400 , 1200 ) General , Allen Brandley Logix 5000 , 500 application ( Motion )

3- Low Pefrormance CPU / Low Price : Delta . ( for simple machines ) .

I think now days Seimens  but earlier it was  Allen Bradley