I miss phone bodies being plastic. Sure, metal feels premium but you can't drop your phone without leaving a permanent mark on it. Not to mention how stupid the idea of having glass background is. These days it's hard to see a phone whose glass is not messed up.
To be honest, peak design for me was Samsung's Galaxy S2. I loved that device. Thin, very light, perfect size for my hands. I'd kill for something like that but upgraded to modern standards. I'd also love to see devices with physical keyboard. I waited for BB Key3 to come out when they decided to discontinue the line. Ended up with yet another Samsung device.