Ferne Clyffe State park is great. Bed and Breakfast/Antiquing in Cobden area was great, Grew up near Champaign, the Natural History Museum and Lake of the Woods park in champaign is nice too.
The Galena area is very nice. Leaving Galana from the north end of town follow the Stagecoach Trail toward the town of Lena. Very pretty road with lots of twisties.
That is pretty up there, you can also do a ferry crossing that is pretty neat & interesting....on the ol Charlie D....
Garden of the Gods park in southern Illinois....went there quite a bit in college the outcroppings of rock cliffs make for some spectacular views. It was a great escape from the Design studio at school.