The best travel itinerary for Chicago depends on your interests and the length of your trip. Here is a sample itinerary to give you a starting point:
Day 1:
Start the day with a visit to the Willis Tower (formerly known as Sears Tower) for a panoramic view of the city
Walk along the Magnificent Mile to do some shopping and have lunch
Visit the Art Institute of Chicago to admire its vast collection of American art
Take a stroll through Millennium Park to see the famous "Cloud Gate" (also known as "The Bean") and take in a concert or outdoor performance
Day 2:
Head to the Navy Pier to see the iconic ferris wheel and enjoy a boat tour of the city
Explore the Lincoln Park Zoo
Visit the Museum of Science and Industry to experience interactive exhibits and shows
End the day with dinner in one of the city's many delicious restaurants
Day 3:
Take a day trip to the nearby city of Evanston to visit the Baha'i Temple
Explore the Hyde Park neighborhood to visit the Museum of Contemporary Art
Visit the Garfield Park Conservatory for a relaxing afternoon stroll through beautiful gardens
End the day with a visit to the Chicago Theatre for a show or performance
Of course, this is just a starting point, and you can adjust the itinerary to best fit your interests and schedule.