I absolutely LOVE In-N-Out burger. Unlike all other drive thru food places they have a simple menu and seldom get an order incorrect.
Look into the "secret menu" items. Some are addicted to the "animal style" fries but I'm not one of them.
I do love that they will cut the burgers into 4 pieces for my little ones. They also have grilled cheese on the secret menu.
I'm a fan of the strawberry milkshakes but I've also heard you can get a napoleon milkshake with vanilla, chocolate and strawberry.