Have to go with the OG, because it was totally different than anything that myself or anyone else had seen before. In that sense, it was most "mind blowing" of them all. I'm in the minority, but I dislike the design of the 4/4s/5/5s/SE when compared to all the others. Too square. 3G/3GS was easiest to hold and interact with. iPhone 6 - present are the most aesthetically pleasing.