Jimmy John, along with High Roller Deli (not on Yelp) are probably the best 2 sandwich places to go in Las Vegas. Of course, I am referring to on the cheap and not places like Carnegie Deli inside the Mirage.
Service is fast (very fast) and the quality is high. I am a new customer and have only tried two sandwiches at the moment. Club Lulu and the "Night something or other." Sorry the name eludes me. I highly recommend trying this sandwich shop out over Subways, over Quiznos and any of the others out there.
I am actually thinking about opening one of these up, not only here in Las Vegas, but out in Orange County when they are ready to do so. Looking for investors. :-)