New Vegas

New Vegas is the post-War version of what used to be Las Vegas, Nevada. Tycho was told about it by his father, who was also a Desert Ranger in Nevada. According to his memory, a fat mobster, similar to Gizmo from Junktown, used to live in Vegas.

Appearances
New Vegas is mentioned by Tycho in Fallout. Vegas will appear in Fallout: New Vegas, an upcoming game by Obsidian Entertainment.

Behind the scenes
The fat mobster mentioned by Tycho is a reference to Fat Freddy, a character from Wasteland.

Speculations
It's possible that in the new game, the NCR, or New California Republic, might make an appearance because of its proximity to Nevada.