Where can I find oysters?
Dominicks and Jewel usually have a few oysters on offer, but...
Since the awesome International Mart closed on I55 and pulaski, I'd say the best closest place would be Isaacson and Stein.
I'd also assume that there's gotta be a place in Pilsen or Chinatown which are both a very quick trip, but I'm not certain. If you are planning to be out further west, on North avenue is Supreme Lobster out in Villa Park: