I'm re-reading Asimov's Caves of Steel, which has always been a favorite. Written in 1954, there's plenty of stuff in it that is incredibly out-of-date, but things that are easy to look past. The big one that stands out is this future Earth (year unspecified, but somewhere in the 3000's) having a population of 8 billion, a population level that has the Earth near its breaking point. It's less about resources (though it comes up), and more about just plain living on top of each other-- that with 8 billion no one could have any "personal" space.

What really stands out, though, looking at it from a writing-critique standpoint, is how it would not survive a critique session done today, let alone get over the hurdles of publication. It has huge chunks of info-dump, just pages upon pages where it's just telling us How Things Are. It also is a complete mess in terms of point-of-view. It's sort of third-person-omniscient, but also sort of third-person-limited from Baley's POV. But even with Baley's POV, it more often tells us what his face is doing rather than what his feelings are.

The big thing I saw, however, is a lot of the Bad Writing Ticks I had a few years ago (namely, large meandering infodumps and messy POV) are right there.

So: learn from the masters, but at the same time, recognize the things of old that don't cut it anymore.