First of all, this summer looks to be pretty epic, music wise.
Second of all, there are 4 great festivals (at least) nearby: Summerfest (Milwaukee), Pitchfork (Chicago), Warped Tour (Tinley Park), and Lollapalooza (Chicago)
These are the bands from the festivals that I care about seeing personally haha. Pitchfork isn't done releasing their lineup, and Lollapalooza clearly isn't, since they're bitches. I'm linking to the sites I found these lineups at so you can check them out for yourself. Keep in mind that on the Warped Tour site, every band listed is not playing every date, so you have to check who'll be in Chicago specifically. If you're tagged, that means I think you care remotely about either the festivals, the bands, or going with me to any of these shows. or any of the above. Hooray. On to the bands...
Summerfest (June 25-July 5)
June 25: Rise Against and Rancid
June 26: the Offspring
July 2: No Doubt with Paramore and Bedouin Soundclash (this is the paying show, there's one every night), Judas Priest, Guster, Shiny Toy Guns
July 4: The Fray with Jack's Mannequin (paying show)
Pitchfork (July 17-19)
July 17: Yo La Tengo, Built to Spill
July 18: The National
July 19" The Walkmen, The Flaming Lips
Warped Tour (August 1)
Anti-Flag, Bad Religion, Bayside, Big D and the Kids Table, Bouncing Souls, Innerpartysystem, Jet Lag Gemini, Less Than Jake, [NOFX are lame bastards and not playing Chicago], Senses Fail, Streetlight Manifesto, maybe The Ataris
Lollapalooza (August 7-9)(none of these are official, the starred ones are vaguely confirmed)
*Depeche Mode, *The Killers, *Kings of Leon, *The Decemberists, Atmosphere, Animal Collective, Band of Horses, Ben Folds, Franz Ferdinand, Kaiser Chiefs, Lily Allen, Matt and Kim, Metric, OK Go, Ra Ra Riot, Rancid, Razorlight, Regina Spektor, Rise Against, Silversun Pickups, Yeah Yeah Yeahs, Vampire Weekend, The Gaslight Anthem, Peter Bjorn and Johnhttp://www.summerfest.com/flash/#app=c436&8b6e-selectedIndex=1&71fe-selectedIndex=0http://www.pitchforkmusicfestival.com/index.php?d=allhttp://www.warpedtour.com/warpedtour/bands.asphttp://www.chartattack.com/news/67852/lollapalooza-lineup-leaked