The NIH, CDC, DoE, NOAA, the various DoD labs (ONR, ARL, AFRL, etc)--and more too. The NSF doesn't have a ton of intramural research, but they have very smart people on staff evaluating recent research and figuring out what to fund next; ditto for DARPA and several other agencies.

It's not just technical stuff either. The FAA has made being shot through the air in a metal tube (i.e., flying) almost absurdly safe, so much so that driving to the airport is more dangerous than the flight itself. I feel comfortable eating food from the supermarket, thanks to the USDA and FDA. The Library of Congress's work is used in libraries around the world; their collections (and the Smithsonian's) are also useful for researchers and fun for the public.

But sure, the real problem is that renewing your driver's license sometimes sucks.