I work at Hungry Jack's as a Team Leader and usually run front counter and drive-thru.
Just the other day, I handed an order to a customer and he accidentally knocked over his drink onto the counter, making a huge mess. I said it wasn't a problem and that I would clean it up for him. Then a lady came up to the counter to order something and looked at the mess saying, "you spilt the drink again, huh?" I know that sounds mean but she was really nice about it. I replied that no, it wasn't me for once, even if I am the clumsiest person that works there. She told me to keep chanting to myself "I will not spill it, I will not spill it". Sounds weird, but it really made my day. =]
And every Tuesday night when I work, a particular man comes through drive-thru and orders a Spicy Chicken Baguette and large fries. Even if it's uber-busy and he's been waiting seven minutes for his order, I sincerely apologise for the wait and he always says, "no worries, I can see that you're really busy. Don't get too stressed!" with a big smile on his face. It's great seeing him on Tuesdays!
EDIT: To the lady who gave me a $5 tip when she was waiting eight minutes on a Vegie Baguette in drive-thru, since the boys didn't listen when I called it over the microphone and was really apologetic: thank you so much, you bought my dinner for me. It was much appreciated after a busy and long shift!
So thanks to those customers who are patient and don't yell at the girls on front counter because their burgers are taking forever to prepare...it's never our fault, it's the boys out back who can't make burgers! You are all wonderful and a pleasure to serve. =]