The Flamingo perhaps since that was the one that Bugsy opened? Forgive me if the book or movie outlines this.

In the final draft of the screenplay Moe Greene's casino is also named The Flamingo. But in the film, the hotel/casino they enter isn't the Flamingo.

They obviously couldn't use the name due to legal issues in combination with a limited budget.

Moe Greene is definitely based on Jewish gangster Bugsy Siegel, who was the first gangster who came to Las Vegas and built a major casino.

Both were killed with a shot through the eye and both were friends with another powerful gangster, Meyer Lansky (Hyman Roth).

For more info, check this out:

http://godfather.wikia.com/wiki/Moe_Greene

http://www.dailyscript.com/scripts/The_Godfather.html

And ofcourse:

http://en.wikipedia.org/wiki/Bugsy_Siegel

Well, that way a quick and easy one!

The Flamingo even has a memorial monument for Bugsy:

http://govegas.about.com/od/flamingohotelandcasino/ig/Flamingo-Las-Vegas-/flamingo0016.htm

Cool.

Just curious, was this Bugsy memorial built before or after 1974?

If post GFII, it would appear that somebody paid attention to Hyman Roth's '...not even a plaque...' homage to Moe Green in response to Michael's "Who gave the order..." question (always one of my favorite parts of the movie).

The last remnants of the original Flamingo Hotel were taken down in 1993 and the hotel's garden was then built on the site of the Flamingo's original structure. So the memorial had to have gone up in or after 1993.