Ill give you my top 5:
1) Gene & Judes - great chicago style hot dog
2) Wieners Circle - great chicago style hot dog
3) Morrie Omallys - great Bridgeport local spot, grilled chicago style dogs
4) U.S. Cellular Field(aka. White Sox Park too bad they are on the road this weekend) - great grilled Best Kosher hot dog with grilled onions, and mustard.
(5) Super Dawg - a nostalgic classic
honorable mention: Portillos
In my opinion you cannot go wrong with the ones above for a basic chicago style dog, or a grilled hot dog with some grilled onions & mustard. Nothing fancy, just a classic Chicago treat.