I'd like Samsung and Apple to collaborate on a brand new phone.
Myself I'm more toward Android, but iPhone device size. Problem, as Android based devices suffer from gigantomania and surprisingly Apple seems to stick with that 4" (probably because of the dominating Chinese market). I bet though that Apple will come up with an iPhone Max at some point (let's see what they show next week).
I just received a S4 Mini yesterday. Nice phone, but I can't wait to get rid of that touchwiz pestilence. Size is quite ideal, almost too large, I actually like the 4" of the iPhone. I must be a tiny guy I guess, but an important element of a phone for me is portability, carrying it in the Jeans pocket all day long. If I was a guy with hands double as large as mine, or a woman with a gucci bag, I'd carry a phablet around with me no problem, but since all I got is some tight Jeans pocket, I need something smaller.
So I'd go with the iPhone this time.
My dream phone (kind of) would be a S4 Mini sized Nexus with thinner bezel, thus larger screen while retaining that compact size. No logo at the front, just black glass with titanium coloured (dark) metal frame. I hate logos on the front, can't stand that Samsung logo on the S4 Mini. Nexus 4 design is perfect, although too large or me and the screen too small in relation.
Man I wish I never undertook that journey finding a fitting smartphone. Miss the good old days where that cell phone was sufficient enough.