At one time, one of the classrooms in the Everitt Lab had a plaque noting that it was the site of the first university lecture on transistors, ever. I assume it's still there, though I haven't been back to the U of I for a while myself.

I never met Prof. Bardeen, but those I know who did said he was one of the nicest and most modest, unassuming guys you'd ever want to meet.

Edit:

An acquaintance of mine was a librarian at the U of I. According to her, even after he retired, he'd come into the Grainger Engineering Library a few times a week to catch up on the latest journals. She said he was always super-nice and polite to the staff. I believe she said he generally just wore a flannel shirt and jeans.