Honestly what is not to love about In-N-Out Burger? They have tasty, well prepped burgers and french fries. Service is 99.9% of the time great - most likely because this burger chain actually pays their employees decent wages and from what I have heard from friends who have worked there - the chain actually does have a good rapport with their employees.
Any In-N-Out I have been to is squeaky clean and employees are consistently cleaning the tables and floors - not just this specific one. At this one in particular I have noticed the drive-thru can start to get a little out of hand, but usually they will send out an extra person to start taking orders.
Why I love In-N-Out over most burger chains - their burgers have a crispness to them, the lettuce is not soggy, the tomatoes are fresh, you can get your onions grilled. The french fries are cut fresh (you can see them doing it). The shakes are very good.
The menu is simple. Yet... we all know of the "secrets" behind what you can order at In-N-Out. I applaud them for not layering bacon and BBQ sauce and all kinds of other crap onto their burgers like so many other chains do.
In-N-Out knows what they're doing and I appreciate that.
PS - This was the very first In-N-Out to open in Las Vegas and it was a ridiculous madhouse when it opened.