It could either be from the one across the Mojave Express, the one next to the Silver Rush or the ones in vice and sin of New Vegas. I choose Gomorrah it has that underground bdsn feeling in it.

The Tops for me personally. My characters have other opinions

I like the Tops, they seem to the most neutral, Benny not withstanding. I can also make the casino a better place to go, and see the results of those efforts. In the other casinos, I am helping a few people who have been screwed over by the casino, but the casino does not seem to change.

Tops definitely - casino, swimming pool, Aces Theatre.... I can actually imagine spending time there

The Tops cause it's the only one on the Strip not run by sociopaths.

'Cept Benny but he's dead now.