It's horses for courses.
Even though there is Bees Putty and all sorts of other ones out there, many people stick to what they are familiar with and what best works for them.
The first question I'd ask is "do I want air drying or do I want to bake things to set them?"
I like Green Stuff... lots of pros use it (normally mixed with other stuff) but they also use all sorts from Fimo to Bees Putty... I really don't think that there is an 'industry standard'.
For me, it's Green Stuff all the way and EBay has it cheap if you shop around
(Normally, I'd have recommended Heresy Miniatures but they don't seem to stock it at the moment).