I found out that the Helios One power plant actually exists (probably without Archimedes).
I also knew Nellis AFB, Hoover Dam and McCarran Airport were real, and some quick Googling showed that Boulder City also exists.
What other real-life buildings exist in the game world? Are the casinos based on real ones?
Here are places that exist in both the game and the real world:
The game also contains numerous locations that are parodies of real-world locations.
I'll start with casinos, since you asked about those specifically:
The Bison Steve casino is based on Buffalo Bill's Resort and Casino. Notable similarities include the large outdoor sign featuring a bison/buffalo and the presence of a roller coaster.
The Vikki & Vance casino corresponds to Whiskey Pete's Hotel and Casino. Vikki and Vance's "death car" and artifacts are on display in the Vikki & Vance's main hall, whereas Whiskey Pete's has an exhibit containing the car and clothing Bonnie and Clyde died in.
The Atomic Wrangler's exterior sign is topped by a neon cowboy who looks somewhat like the iconic Vegas Vic. The Wrangler moves one of his arms, much like Vic did before 1991.
The Silver Rush's sign looks a lot like the sign the Golden Nugget used in the middle of the 20th century.
The Lucky 38 casino bears a resemblance to the Stratosphere tower.
The Gomorrah is based upon the former Dunes Hotel & Casino, now replaced by the Bellagio. They share faux-Persian décor and theming, and have similar architecture. The Dunes was also the first hotel on the Strip to offer topless performances.
The remaining in-game casinos (The Tops and The Ultra-Luxe) do not seem to be based on real casinos.
And now for other locations:
Bitter Springs camp and Bitter Springs Recreational Area are located roughly along the path of the real-world Bitter Springs trail.
Camp Forlorn Hope is located at Forlorn Hope Spring.
Camp Guardian is located at Guardian Peak.
Camp McCarran is set up in the remains of McCarran International Airport.
Freeside is meant to be the remains of Fremont Street.
Helios One is a reimagining of The Solar Project.
The Ivanpah Race Track is based on an abandoned race track south of Primm. There's not much information about it online, apart from a few mentions in relation to the nearby Ivanpah Solar Power Facility, but it's visible on Google Maps.
Jacobstown comprises the remains of Mount Charleston Lodge.
The Jean Sky Diving shack is presumably located in the town of Jean.
The NCR Correctional Facility seems to be the now-closed Southern Nevada Correctional Center.
Novac's T-Rex, Dinky the Dinosaur, is a play on the Cabazon Dinosaurs, Dinny the Dinosaur and Mr. Rex.
The Southern Nevada Wind Farm may be a reference to the Searchlight Wind Farm, a wind power plant that was planned at the time of the game's release and has since received government approval.
The Welcome to Fabulous New Vegas sign is a modified version of the remains of the Welcome to Fabulous Las Vegas sign.
In the game, a monorail system connects Camp McCarran with the Strip. Las Vegas does have a small monorail system, but the portion of the monorail connecting the Strip to McCarran is only in the planning phase.
This list is incomplete. Anyone can edit it to add or correct stuff. To look for entries to add, go through the list of F:NV locations at the Fallout wiki. There should be a note if it's a real world location.
There are so many other ones, but here are a couple...
Just to name a few more.
The reppcon rocket museum is based on the Pepcon rocket fuel factory. however it blew up in 1988
Helios One is actually based off of a solor energy power plant called Solar One
Also, Nipton is not in Nevada, it is in Calafornia
(I know all this because i live in Las Vegas)
It's hard to tell if Vikki & Vance is based on Whiskey Pete's or Primm Valley Resort & Casino or both. The Bonnie & Clyde exhibit was moved between casinos a few times. And, the wiki page for Whiskey Pete's claims that it didn't get the exhibit back until 2011; Fallout NV was released in 2010.
Considering when the game was being developed, the Bonnie and Clyde exhibit should have been at Primm Valley Resort & Casino. Flicking through the web-archive of the RoadsideAmerica article is the best evidence for this. In June 2009 and March 2010, it shows that the exhibit was at 31900 Primm Valley Blvd, which is the address of the Primm Valley Resort & Casino. Immediately after that, the archive shows that the exhibit was moved to a casino in Verdi, but it also states 'Normally at Terrible's Primm Valley Resort ... I-15 exit 1, southeastern side'. It's unclear if this specifically refers to the old name of Primm Valley Resort & Casino, or the old name of the resort as a whole (that gets confusing). But I notice 'I-15 exit 1, southeastern side'. Primm Valley Resort & Casino really is South East of this exit whereas Whisky Pete's is West of the I-15. Help me out if that's not how this works. This is the most credible thing that I could find online which pins down the Bonnie & Clyde exhibit pre-2010.
That being said, Whiskey Pete's has been associated with the Bonnie & Clyde exhibit for a very long time so it could still be the inspiration behind Vikki & Vance. I've liked looking at this forum which has a few people who were tracking the Bonnie & Clyde car years ago. There's also this blogpost. In both of those, there are claims that the Bonnie & Clyde exhibit was in Primm Valley Resort & Casino even earlier than 2009, but there's also evidence that people associated the exhibit with Whiskey Pete's during that time. Should also point out that Whiskey Pete's might always have had ownership of the exhibit.
Moving on, the location of Vikki & Vance has similarities with both casinos. It's East of the Freeway like Primm Valley, but it's opposite Bison Steve's like how Whiskey Pete's is kind of opposite Buffalo Bill's. Personally, I think the exterior of Vikki & Vance has more in common with Whiskey Pete's, but it's not a total recreation of either casino. I have no idea about the interior.
Vikki & Vance was probably a combination of both.
Sloan exists but it's less a town and more a collection of big mines and a small truck stop but its right outside of Vegas right where Sloan is in the game. I also looked and saw that the Ultra-Luxe is probably a mix between the architecture of the Bellagio and the sign of the Luxor.
The Ultra Luxe is based on the Bellagio.
The Mojave Memorial Cross or Mt. Soledad Memeorial Cross may have been inspiration for the Yangtze Memorial.
I think that the alien space ship that crashed in the lower area of the map is a reference to Alien Fresh Jerky restaurant in Baker, California.
