If you're looking for a classic German place, then the Chicago Brauhaus in Lincoln Square is tremendous.
Classic Steakhouse would probably be Gene and Georgetti although there's other good steakhouse options...
Classic Pizza... there are many but my fave is Pizzeria Uno and Due
Classic Italian... Bruna's
Classic Bar... I gotta give it to the Map Room, the world's greatest microbrew beer and ale bar.
Classic Thai... Siam Noodles and Rice on Sheridan, though it's a bit run-down and pedestrian it's pretty much hardcore authentic basic Thai.
Classic Mexican... Topolobampo is the restaurant that started the whole "haute Mexican" movement in Chicago.
Classic Haute Cuisine... Charlie Trotter is probably the longest-running act in high-end creative haute cuisine in the city.
Classic Rustic French... Cafe Bernard
Classic Cajun... Heaven on Seven has been running quite awhile although Blue Bayou is really good also.
Classic Sushi... Kamehachi, long-established in Old Town...
Classic Deli... the Ashkenaz at Rush and State although some might say Manny's is truly more "classic"... i.e, more linoleum.
Classic Hot Dogs... the Wieners Circle, especially after midnight on Friday or Saturday night.
These are a few of what might be considered classics in their respective categories.
re: Chicago Mike
Good list. Couple of notes:
I'd have to add Tufano's/Vernon Park Tap to the classic neighborhood American/Italian style resto. (1073 W Vernon Park Pl # 1,) Near IUC campus and Al's Beef (another classic?) on Taylor Street.
And Manny's, not to my mind a great deli, but if want to see what a Jewish cafeteria was like (as well as sample some fine carved sandwiches), that's the place. Truly an institution. http://www.mannysdeli.com/
Manny's and the Whitestar have been around and are classics for Chicago. Also, not a restaurant but definitely a Chicago thing to do is hit the Maxwell Street Market on Sunday mornings.
The Pump Room is espeically famous and definitely a Chicago classic. I heard that they have a new chef and that the food is top notch
The Pump Room is a Chicago classic, however I read on their website that they will be doing a remodel starting in March of 2007, and lasting 4 months. It also mentioned that service will continue @ Byfields across the lobby.
I am looking forward to returning to The Pump Room as soon as the renovations are complete.
Well, there's "been around for a bit" and "been around for even longer". ;)
For example, the deep-dish pizza places like Giordano's, Gino's East, and Uno's all started in the 1970s.
Lou Mitchell's, known for their breakfasts, started in 1923. If any place in Chicago is a classic, that's it. www.loumitchellsrestaurant.com
The Billy Goat Tavern opened in 1934 and moved to its present location in 1964. It's another local institution, all the more so thanks to Saturday Night Live. "Cheezborger! Cheezborger!
No fries, cheeps! No Pepsi, Coke!"? www.billygoattavern.com
Gene and Georgetti, the steakhouse, was founded in 1941. www.geneandgeorgetti.com
The Lettuce Entertain You empire was founded with the opening of R.J. Grunt's in 1971. www.leye.com
Frontera Grill, the Mexican restaurant, recently celebrated its 20th anniversary. www.rickbayless.com/restaurants
Walker Brothers Original Pancake Houses in the suburbs were founded in 1960 as a franchise of the Original Pancake House chain which opened in 1953. www.walkerbrosoph.com Their famous giant apple pancake has a much longer history in Chicago, as its popularity was mentioned in a Chicago newspaper article in 1905. (There was an article about apple pancakes in the Chicago Tribune in January.)
Don Roth's Blackhawk was around in the 1920s. The restaurant on Wabash closed in 1984 but the Wheeling location, opened in 1969, remains.
Hackney's, the chain of restaurants serving burgers and onion loafs, started in 1939, but traces its history to the 1920s. www.hackneys.net
The Parthenon, founded in 1968, claims to be the oldest Greek restaurant in Greek Town.
What do you mean by "classic"? Places that have been around for a long time (e.g. Lou Mitchell's)? Places that are among the very best restaurants in the country (e.g. Alinea, Avenues, Everest)? Places that are unique to Chicago (deep-dish pizza)?
If there is a particular kind of food or kind of restaurant, or a particular neighborhood you will be visiting, it will help narrow down recommendations among the thousands of restaurants here.
Berghoff's re-opened but I'm not sure of the exact status, and I've heard that it's only part of the original restaurant; I'm sure others here can elaborate.