Just the first book in the series was required, I hope.
Yes! I myself had several false starts with the Dune Messiah and Children of Dune going back to 1980 or so. I finally read them in the 2000s after watching the SciFi Channel's follow-on "Dune" series.
Same thing with Gibson: Neuromancer is excellent and holds up really well (as does more than half the anthology Burning Chrome that preceded it), but Count Zero hasn't aged as gracefully and wasn't as good in the first place. I recall actively disliking Mona Lisa Overdrive when it came out, so neither of the latter two "Sprawl" books were assigned.
We can defeat gravity. The problem is the paperwork involved.