If you're over 40, chances are good that you've enjoyed (or at least that you've been served) liver and onions, probably when you were younger.
If you're under 40, chances are good that you don't even know what a liver looks like.
Last year, I was having dinner with some thirtysomethings at mk (868 N. Franklin, Chicago). On a lark, I ordered the beef liver and onions. Neither of my tablemates had ever had beef liver before, or liver in any form other than pate and foie gras. When my dinner arrived, one of them remarked, "The liver is not nearly as horrifying as I thought it would be."
I like liver, and I regularly eat offal in other forms, like tripe and tongue and sweetbreads. All these organs are what Italian chefs call "the fifth quarter" of the animal.
These animal parts have a distinct organ-y flavor, and though many, like me, sometimes order these meats, few would probably prefer offal to a steak, chop or leg.
Still, liver is tasty, liver is good for you (high in iron), and if you really like chicken liver, Chicago's Home of Chicken and Waffles is a good place to go for it. The chicken livers there are also a huge value. You get a lot in every order (perhaps because they process so many chickens there, and so few people order the livers, they have a lot of livers in inventory just waiting for someone to buy them).
Liver and onions are a classic combo, and one of the reasons those flavors are so complimentary is that onions are sweet and the liver, because it's a blood-filtering organ, has mineral notes, specifically of iron, and its slight bitterness is balanced by the onion's sweetness. At Chicago's Home of Chicken and Waffles, there's always syrup on the table. Try some syrup on your chicken livers – and consider ordering a stack of buckwheat flapjacks (pictured) on the side. Thank me later.