Yeah, agree with Enjoyed, almost no one will know Underworld (the band) if you ask them, save a few that will say, oh, they did that track off the film Trainspotting. I'm sure thousands watched the Olympics in 2012 and remember the moment with the Isles of Wonder track, they may have later bought the soundtrack to the opening ceremony and read on the back of the Cd that Underworld wrote the track, they would've thought, who the hell are they.
As Daft Punk aren't around doing anything these days I'd say in terms of popularity in my area, or if you asked 100 people in the street etc, they would be familiar with The Chemical Brothers, then, Daft Punk, then Underworld.
Wierd fact from me: Bosco, you mention Chems tracks you heard on Chicago radio, . . well the most geographically distant place I heard a Chemical Brothers track on the radio was in the Falkland Islands, I was down there in'99 (in the Navy at the time) and I heard HBHG on the radio, I knew they had a new album coming out so it was great to hear this new song from them, it sounded great on first listen, really different, could tell it was a killer track.