Blue Sky is still Ok. There is a couple of new options in that area: 1st Choice (http://www.1stchoiceohareairportparking.com) that's very similar to Blue Sky, but is a block closer to O'Hare and cheaper, and Preflight (https://www.preflightairportparking.com/), where you park yourself in their garage and take a shuttle. I haven't tried the latter, but heard that shuttles run very often.