Here is a list of the Revelation Space Books Ranked, According to Goodreads.
The Prefect
Goodreads Rating: 4.16
Redemption Ark
Goodreads Rating: 4.15
Chasm City
Goodreads Rating: 4.13
Inhibitor Phase
Goodreads Rating: 4.12
Galactic North
Goodreads Rating: 4.12
Absolution Gap
Goodreads Rating: 4.02
Diamond Dogs, Turquoise Days
Goodreads Rating: 3.98
Revelation Space
Goodreads Rating: 3.99
From the blurb:
Nine hundred thousand years ago, something wiped out the Amarantin. For the human colonists now settling the Amarantin homeworld Resurgam, it’s of little more than academic interest, even after the discovery of a long-hidden, almost perfect Amarantin city and a colossal statue of a winged Amarantin. For brilliant but ruthless scientist Dan Sylveste, it’s more than merelty intellectual curiosity – and he will stop at nothing to get at the truth. Even if the truth costs him everything. But the Amarantin were wiped out for a reason, and that danger is closer and greater than even Syveste imagines …
REVELATION SPACE: a huge, magnificent space opera that ranges across the known and unknown universe … towards the most terrifying of destinations.