The place is always, always packed. There are locals, taxi drivers, limos, every type of patron lined up inside and in the drive-thru. Blame it on the location (close to the strip).
As per every other In-N-Out, service is quick and friendly. Everything is done with practiced ease and efficiency. They rarely make a mistake in the drive-thru window as well, which is amazing considering the volume of customers.
I always get #2 (cheeseburger with fries and a drink) but make the fries animal style. With banana peppers. Ace!! Such a west coast classic.
Good luck finding seating during peak hours though!