Default [Q] Seeking newest Google, flagship, vanilla Android smartphone

Senior n00b needs direction. If I'm in the wrong place please correct me.
The latest edition of "XDADEVELOPERS' Android Hacker's Toolkit"
says in part: "Periodically, Google releases one phone in conjunction
with a device manufacturer. . . phones are vanilla Android installations
with no interface or op system customizations. . . . are highly prized
by ...hobbyist communities. Etc. . . .
Chapter 11 refers to NEXUS S as the second Google, flagship, vanilla
Android smartphone.

QUESTION: What is the newest Google, flagship, vanilla Android smartphone.
Thank you