No idea how the N5 gets top spot. Horrible battery which just kills it. G2 is, on paper, the same thing, but slimmer and with a huge battery.
Its hard to gauge what is best and what is not. Every phone is different and each phone appeals to different users.
I believe it is best because its a phone that includes highend specs, a reasonable battery life, and looks great with no bloat added(not everyone roots thier phone and installs a ROM) plus the phone comes at a price that the majority can afford.
Get why its best now?