There are still a few around. Up north, there's one on Rollins Road at Washington Street in Ingleside (just south of Fox Lake), and on US 12 at Golden Hawk Road, north of IL 173 in Richmond.
There is also a former Dog 'n Suds on IL 120 (Elm Street) on the east side of McHenry; but it closed over twenty years ago and has been a used car lot for just about that long. The Dog 'n Suds sign is still present, although it was painted-over.
I think that there's also a DnS near Rockford, but I've never visited that one.
There was a Dog N Suds out here in St. Charles a long time ago-it had long since become something else by the time I remember it in the 80's You can also still find Dog N Suds root beer in bottles in a few stores-a local grocery store here often has it.
I've eaten at the one in Richmond a couple of times-it's on the way home from Road America.
<a href="http://www.flickr.com/photos/williamdhopkins/3664223016/" title="Dog 'N' Suds-Richmond, IL by William 74, on Flickr"><img src="http://farm4.staticflickr.com/3312/3664223016_8cc2940c3c.jpg" width="500" height="333" alt="Dog 'N' Suds-Richmond, IL"></a>
There is still a Dog N Suds in Loves park, IL that operates in the summer. I remember one in Crystal Lake also back in the 70's. It turned into some other kind of Vienna Beef place and now I'm not sure if the building is still there or not.
There used to be one in South Holland, at or near the southwest corner of South Park Avenue and 170th St. (across from where they build Thornwood High School).
There also used to be on in Lombard, a popular place to hang out and cruise through. I remember a friend pulled a prank and put one of those lawn jockeys on the roof at the front of the drive through (so you could see it from the street). Don't remember the street it was on but, it was the east side of downtown Lombard. We used to call it the "Arf & Barf" as the food was not too good.
The original building for a Dog 'N Suds still stands on the northwest corner of 154th and Cicero in Oak Forest. I was there one night in the summer of 1966 when a Corvette drove in with squealing tires and split his hood in two when he hit one of the angled pipe roof supports. We all gave him a round of applause! The building is now being used as a pickup truck bed camper cap company. There was also an A & W Root Beer stand on the east side of Cicero near 153rd across from the Oak Forest Bowl. That structure is now gone.
Last Arf & Barf I remember was in Waukegan, just east of Green Bay Rd.on Belvidere, when we moved there in 1969. It closed, and then they built a Dunkin' Donuts in front of it on the lot, then tore it down.
There was a Dog N Suds in Lake Zurich Illinois on Route 12 that is now Papagus Gyros. 454 North Rand Road. I remember it well and the building now still looks like a Dog N Suds. Not meaning to get to far from Chicago but in Byron, Illinois there was a Dog N Suds at 705 West Blackhawk Drive. It is now Sam's Drive In. The building still has the root beer sign.
Back in the early 60's we use to hang out at Dog N Suds on Cicero & Southwest Hwy. It was a good date place. It had minature golf connected to the drive inn. Back then you would pull in and open the hood of your car to show off your muscle. Every weekend it was what you call now a car show or meet. Another place was Henery's Hamburgers on Archer and Cicero.
There was a Dog N Suds in Wheeling on Route 83 just south of Dundee Road. The drive in still stands but has a new owner and name. Just north of Dundee Road on Route 83 in Wheeling there was a Henry's Hamburgers that closed in the early 1980s.