What is the best PLC type?

Answer 1

That really depends on what you have to do.
In the US the Allen Bradley ControlLogix is king.
But Automation Direct sells a good PLC at a great price.

Answer 2

It depends on what you are going to do with it. If you are trying to add it to a network that already has a bunch of them from a specific manufacturer then going with that brand name is the easiest. If you need to replace an older bulky one that has become obsolete then an equivalent newer compact one from the same manufacturer is more likely to be able to reuse the old code (but not guaranteed since some conglomerates buy up other manufacturers and don't try to make any compatibility for their users.)

A-B tends to have the best software development packages since they spend a lot of money on engineering and updating those packages.

In the long run your biggest cost will be the design and coding of the application software, the commissioning of the PLCs with that application software, and the on-going updates. Go with a PLC that makes that easy and effective and your PLC system cost will be minimized.