My wife has a Nexus 5 which is cheap to repair and replace parts. She's so happy with the phone she doesn't want a new one (Shame Google stopped makeing excellent, upgradeable, repairable and cheap smart phones).
Also, the Nexus 5X is out, almost identical, but based on the LG G4 instead of the G2, and has a small handful of niftier features, including better battery life.