Nexus 5. Marvelous beauty of a phone. Red panda is especially beautiful. Screen size was just about right at the time, the way the screen blent into the bezels was amazing, the ergonomics were awesome.
I found the Nexus 5 (not the 5x) had poor build quality - it was plasticy, and mine fell to pieces after 18 months - the battery started to run out early, then the microphone, and eventually it just stopped working at all.
It had a nice interface, but I moved to the HTC One (installed GPE on it), got a rock solid case and after 14 months it feels like it hasn't aged a day.
