The conservatory had a special showing of dinosaur bones mixed in with the flora and fauna when I went. Although I recommend the conservatory for seeing all the different plants, I can definitely say don't go during the middle of the summer. The temperatures inside must have exceeded 105. It was very hot and humid inside. Overall, it's a good trip for a couple of hours during the day and if you go during a special exhibit, it's even more fascinating.
The Art Institute of Chicago contains many beautiful works of art. It will take a full day to see everything the museum has to offer but I love that each culture and time period in art history has its own space at the museum. As I said it will take a full day to view everything but if you want you can do a room at a time over a span of days in order to get the full impact.
If you're looking for an affordable day spa with great service in the heart of downtown, look no further than Mario Tricoci. Their package prices are quite affordable (starting in the $130 range and working up to about $370). Their staff were quite helpful, courteous and pleasant. The only reason this got 4 stars instead of 5 is that during the make-up consultation, the facialist recommended products containing chamomile even after she was told I suffered from seasonal allergies (namely ragweed).