For some reason, I was craving a deli sandwich on our most recent trip to Vegas (almost sounds like a that's what she said). Greenberg's is cafeteria style in NYNY Casino. A very cool little food court with lots of options (it looks like the streets of NY). You can get pizza, or hit a Sports Bar. It's all there.
The pastrami sandwich I got was average. If you need a quick on the go lunch on the south end of the Strip, stop by NYNY and check out what they have done. It's one of my favourite lunch stops in Vegas (the food court).