Aerogel [Edit: 1931! Amazing.]
MRI scanners?
Solar cells
Side point:
Looking through this thread there's a lot of "that doesn't count as it's based on something previous", but you have to define a cutoff point. At what point does two items no longer fall into the same category? If you want to be really picky then you can trace everything back to being the same as each other or using the same technology or ideas, but you have to make distinctions.
A landline phone and a cellular phone are both telephones, but they aren't the same. Yes, if the original hadn't been invented then the mobile wouldn't have come along - but in the same vein if humans hadn't developed the ability to talk then we wouldn't have had the telephone!