Every once in a while, a revolutionary product comes along that changes everything. Those were the words spoken as Steve Jobs hit the stage and introduced the very first iPhone to the world after having spent two and a half years working on the device. Looking back at that keynote, I'm not so sure everyone at that time felt the same way about it but if they didn't then, the chances are good that they do now.

The iPhone as a product has arguably gone on to reshape not only the smartphone industry but the wireless industry as a whole and while the very first iPhone takes much of that credit for a lot of people, a recent thread in the iMore Forums asks which iPhone do you think broke the most ground for Apple? Was it really the very first iPhone that took it mainstream popularity or was it another iteration?

I'm still of the opinion that the 3GS was what pushed the iPhone into the much bigger area of mainstream popularity.Speedygi, iMore Forums Member

By production count, the iPhone 3GS is reportedly the most popular iPhone having a production run of 1181 days; followed by the iPhone 4, produced for 1174 days and for a lot of folks, that seems to be the device that really sparked their interest in Apple's iPhone offerings.

The iPhone 4. With the new body and retina display people took it seriously. AT&T exclusivity ended.sting7k, iMore Forums Member

For others, it's the iPhone 4 which brought about a whole new design at the time and marked the end of AT&T's exclusivity on the device. At that point, the device became more accessible than ever before and the masses wasted no time grabbing them. If you really think about how many iPhone 4's you still see out there today, I bet it's a lot.

So let's hear it. Which iPhone do you think broke the most ground for Apple? You drop your in the iMore Forums or let us know below in the comments section.