Stayed at most of the Sheraton and Points in the Chicago area in the past few months, so I'll chime in on a couple:
1. Sheraton Chicago Heights in Arlington - the new waterpark is huge. Was there on business, but took a walk through it and would definitely recommend for families staying wtih kids. Only downside is that it is ~15 miles from downtown.
2. Four Points Michigan has great rates and nice/new rooms. Close walk/cab to almost everything. Beware the junior suite rooms if you book online - they aren't suites, but are deluxe rooms. There is no separate room, just a sitting area next to the bed. After emailing mgmt about the issue, they said they were aware of this and were working with IT to get the description changed - no points and not much of an apology - but for ~$125 in downtown Chicago, I can't complain much.
3. Sheraton Towers chicago - while the rooms aren't as new as the Four Points, I've found the desk staff and their "CEO - Chief Experience Officer" very responsive and focused on customer service - upgrades with out asking (no full suites) to club level and choice of views. Also, had one issue with a reservation mix up (long story) and they credited 1,500 spg for the mix up - which was more than generous considering the mix up was partially my fault! While others have dogged on the Sheraton Towers - I'd like to see all SPG properties have the same level of customer service!