But this morning, we tackle some restaurant items that were new to us and our experts.
You might not examine them closely when you use them or think of the hundreds of people who have touched them before you. And neither had we. Until now.
We're talking about the condiments and menus on every restaurant table.
Which harbor the most germs?
Ketchup. Mustard. Salt. Pepper. Sugar. The menu. Which tabletop item harbors the most bacteria? We asked people on the streets of Washington, DC to make their guess.
Crystal says she's going to go with the ketchup.
"Because ketchup goes on a lot of different things so that means that a lot of different people are possibly touching it," she said.
Amanda says she thinks it's the menu.
"Because everyone touches it, including the waitress. And I used to wait tables, and I know how often you wash your hands."
"Well, in my opinion, it would be the salt and pepper."
We'll tell you the correct answers in a minute, but first here's how we did our little study.
We tagged along undercover while a researcher with the University of Arizona swabbed the items on the tables of 12 restaurants in three states: New York, Ohio and Arizona.
Then analysts at a lab examined the swabs for total bacteria counts and coliforms – a broad class of bacteria found in our environment. The presence of coliforms can indicate fecal matters.
"These are objects you're going to touch that can serve as vehicles that are transmitting micro organisms that can potentially make you ill," said Dr. Chuck Gerba of the University of Arizona.
And they're objects in the area where you eat, which gives the germs a pathway into your body.
We asked Susan what items she thought had the least germs.
"I'd say the sugar," she said.
Yup, sugar had the lowest average count, with only 2,300 bacteria.
"Probably fewer bacteria on the sugar, because it might be handled less," Gerba said.
When we asked people to guess which item is the germiest, ketchup got the most votes, but actually, ketchup, mustard and salt all fell in the middle at every restaurant we visited.
Pepper was another story: it had the second-highest average bacteria count with 11,600 organisms.
"Sometimes pepper can have a large number of bacteria in general. Bacteria do like pepper. There's stuff to grow there, so probably - maybe pepper's used more?" Gerba said.
So what tabletop staple was number one in our anecdotal test?
"I'd say the menu," said John. "Because everybody touches it, it gets more hands on it. You know, a lot of people don't touch the other things there."
Ding, ding, ding.
If you guessed menus, you're right. The menus carried the most germs, with an average count of 185,000 bacteria.
"You probably have about 100 times more bacteria on that menu than you do a typical toilet seat in the restroom," Gerba said.
"Haven't you ever gone to a restaurant before and you stick to the menu? I've done that a lot of times. Sticky menus are not really on my diet," he added.
So the next time you eat out, keep in mind that you may be getting more than what you ordered – from the menu.
Most of the bacteria we found are not harmful, but experts say the most common illnesses you can pick up are respiratory infections.
Their advice is simple: place your order and then go wash your hands before eating. And keep the menus away from little kids since they love to put them in their mouths.
As for whether there's a difference between plastic and paper menus, experts say paper menus retain fewer germs than plastic ones do. Paper is not a great breeding ground for germs, but plastic allows bacteria to hide and grow in the tiny crevices.