1. “I didn’t get any dinner!” or “I obviously hated this! Haha!” when the plate is licked clean. My typical reaction in front of the table:
I am happy that you enjoyed your meal, but I only appreciate this joke when I'm the one that cooked, served, and ate the meal with you (e.g., my friends and family). Otherwise, you're just giving your waitress a two-second heart attack, because she'll think something is really wrong at first.
2. Me: “Can I get you anything else?” Customer: “A million dollars? Teehee!” Really, you're going to tease your waitress about giving you money? Excuse me while I get a can-opener for the worms and whoop-ass we have in the pantry.
Sometimes I think the customers that tell this "joke" might actually mean it, though, because they usually turn out to be shitty tippers. If you're serious about needing that million bucks more than I do, then maybe you shouldn't be going out to eat?
3. “The computers are down? So everything’s FREE, right? huehuehue”
Happened to me when I waitressed in a Mexican restaurant: Not only am I in the weeds, but our computer system just froze and died at 6:30 p.m. on a Saturday. Now we get to transcribe orders to the kitchen/bar, hand-write all the checks, add items up, calculate taxes, manually charge credit cards on something that resembles a Victorian-era sewing machine, and respond to this joke from every table. (People who are cashiers: I really feel for you when a barcode won't scan. I know you folks hear this a lot, too.)
4. When I place the bill on the table:
I'll then say, "It's free with every meal, sir."
Just... seriously, people, don't joke about not paying your damn check.
5. "The food is great! You're a good cook! Oh, you didn't cook it? *chortle*" Oh, let's laugh about how my skills are limited to smiling and ponytails. Now, this one would be cute if I didn't find it a bit condescending. I actually am a good cook (and I have references, what up), but the customer here is, in a sense, dumbing me down to an employee who simply brings the food from the kitchen to the table. And that's when I kinda feel like this:
(In other news, I had a fun evening: softball practice with some former co-workers, including my fiancé, and then a great dinner. It was a nice day off.)