I remember when the iPhone 4 first leaked on Gizmodo, with the whole internet going crazy about just how "ugly" that phone was. Right after the announcement, the public opinion shifted towards loving that phone. Though I personally like the iPhone 5 design much better – it feels a lot thinner and lighter, and the slightly larger screen was a great upgrade back then.
After the iPhone 5, my favourite design actually is the iPhone X. Apart from the fact that it's far too big, the design itself looks great, with its stainless steel frame, clean glass back and well rounded proportions on the front. You can say whatever you want about Apple's notch, but at least it has a consistent edge radius and border size across the entire device, as opposed to many other phones where the designers sometimes added a chin at the bottom, inconsistent border sizes at the sides and top, and on top of that, a much harder curve on the notch compared to the screen edges.