The Museum of Science and Industry (Chicago).

One of the big classics. It once contained exhibits from major manufacturers. US Steel, General Electric, RCA. AT&T, IBM, Whirlpool, International Harvester, the Santa Fe Railroad... Most of the corporate sponsorship is gone, it's more "educational", and it costs $30 instead of being free.

Museum of Broadcast Communications (Chicago).

This was once impressive, and now it's closed with the artifacts in storage. It had much early TV studio equipment. Their nostalgia exhibit, pre-Internet, was that they had a huge library of TV shows on VHS tapes, and you could request that one be played for you.