Honestly, most housing. Think about it, shelter is one of the basics! And a house is almost always a wise investment for later.
I grew up in a 1960s era house. My grandmother's 1920s house is still in great condition (and standing, in earthquake-prone Los Angeles). Lots of early 1900s buildings are still around on the West Coast, and lots of MUCH older housing is around on the East Coast.
Canning supplies will still be reliable. Iceboxes/refrigerators might make it (my grandmother had a 30+ y/o fridge growing up). Some cars might, probably the ones that are less-electronically inclined. I can foresee '57 Chevy's still on the road, assuming one could find parts still. All in all, lots of 50-year old things aren't THAT unusual. Heck, my parents
well, I guess that'd be me, in 50 years. They'd be centarians by then.