First of all, let me state that this place was so packed when I get in there that most fast food places would have been eaten alive by the crowd.  Here, however, they calmly churn through the people and I still had my food within 10 minutes.\n\nBeing an In-N-Out virgin, I didn't know what to expect.  However, I got some tips from a friend's boyfriend about this whole \""secret menu\"" business, and decided that mustard grilled was going to be the way to go.  \n\nIt definitely was.  This may have been one of the all-time best fast food burgers I've ever had.  The fact that the burger comes deluxe automatically is a big plus for me.  Definitely a good decision on my part to go here while in Vegas, which I only did because of the fact they were mentioned briefly in \""The Big Lebowski.\""