Great, great, great tasting burger! Probably the best in Oshawa. It's too bad it is located in downtown Oshawa, not exactly the safest area. But location aside, the Patty Shack itself has very friendly service, clean dining room, great marketing and great food. I had the 8 oz. burger combo with fries, can't go wrong. All kinds of creative and interesting toppings (except no fried egg option). Apparently they do great wings as well, going to try that next time along with the Power Pounder burger!
Here are the best burgers I've had in the Durham area in order of ranking...
Pete's Big Bite
The Patty Shack
Shake, Rabble and Roll
Baldwin Street Burger
Montana's Firecracker Burger
Also try Burger's Priest in Toronto!