Anything in the Slammerverse could be made into a serial form, again with a little work to preserve continuity. It's already got a lot of material in the anthologies, so it shouldn't be too hard. Hell, if you could get Drake to revisit the Lacy and His Friends universe, it would be rather timely.
A series based on Niven's Gil the Arm protagonist would be fun for a series or two--the writing chops required could be found in anybody with experience writing crime dramas or who-dun-its, with a bit of extra worldbuilding for organlegging and telekinesis.
Maybe something based on The Stainless Steel Rat? Harrison is dead and buried (sadly!) so he wouldn't be too offended.
Honestly, the problem with a lot of science-fiction books is that, once the core ideas are explored and the conflict resolved, it's best to kind of move on.
EDIT:
Actually, a post-apocalyptic series based on Lucifer's Hammer or War Day would be great. Jericho actually had its moments, but went too soon.
Comedy option for HBO: The Stone Dogs.
Even better option: a port of Turtledove's World War alternate history.
That's something I'd love to see.
Especially since there is a remarkable lack of WWI era movies after Paths of Glory that were anything like decent.
I'm also enamored with The Culture. Not any particular story, really. Just the setting of post-scarcity + friendly AI. It's like an inverted Star Trek. Everyone is having a blast, and interference is pretty much a moral requirement. Apart from a sitcom set on some GSV, Special Circumstances provides all the setting necessary for tons of fun.
Both worlds would have ample opportunity for sex, drugs, nudity and violence. (Which is the only reason I bother watching Game if Thrones these days.)
Asimov's Robot books may also be prefect for HBO. Sorta like a hardboiled detective, except robot minds. (I enjoyed those a lot more than Foundation. While fun rides, the basic premise of predicting everything via psychology is just... eh, unrealistic.)
It has a enough different plot-lines to interest many different audiences I think.
https://en.wikipedia.org/wiki/Chris_Cunningham#Neuromancer
TV or film, really. The distinctions between the two have been greatly blurred these days, for better or for worse. Film, I suppose, is still considered a purer medium, though. Unfettered by commercial interruptions, and syndication or serialization concerns...
HBO should give Dune the high production values grand costume drama adaptation it deserves.
The movie covered some parts well, and the vision was more or less there, but I still left the cinema annoyed. One movie isn't long enough to cover the book, and there's enough content in the books to make many series without having to pad episodes out.
You could do a fair bit of David Ramirez's Forever Watch with practical effects, and the story has enough twists that you could get a long season out of it. Basically set on a colony ship, where people have strange psychic powers, investigating sudden deaths that the regimented ship's society covers up. It might be better as an anime though.
The First 15 Lives of Harry August by Claire North requires almost no cgi, just period stuff and practical effects. Basically everytime certain people die, they are born again and remember their whole life. Of course someone decides to change the future.
In the Country of the Blind by Michael Flynn is about people who use statistical processes to predict the future, starting before lincoln. It could make good tv, especially with the steam punk element. Nice way to talk about machine learning and big data.
The Chronoliths by Robert Charles Wilson. Basically these large sculptures start getting sent back through time something like 40 years, commemorating a warlord's victories. Really strongly written characters, and a good plot.
For batshit insanity and HBO skinflick appeal, maybe L. Ron Hubbard's Mission Earth.
That should be the ultimate criteria, is hard to translate right a deep argument to TV (and sometimes the translation includes "sponsored message" from government and groups of power that damages the book message), but books with good visuals may be perfect for that media (and if are not great, run low risk of corruption)
Would hate that great books like Hyperion end having the same fate as All you zombies or Mimsy were the borogoves.
I have the feeling it would be better as a high quality animated series.
I'm not sure at all how the ending would get translated to film but god would it make for a great movie.
I would be completely contented with a three- or six-part series, but I could also see it being turned (well) into a longer thing by interpolating.
Similarly, but probably more accessible, "The Sparrow" by Mary Doria Russell (and it's sequel "Children of God"). It would definitely do better as a long series.
It has the makings of a TV series as Bill's adventures are already serialized in the books.
Sof of Man by Silverberg would be my other choice. A fantastic book, it would make an eerie and atmospheric production on screen.
#2. Frank Herbert's "The Eyes of Heisenberg".
#3. Alfred Bester's "The Stars My Destination".
#4. "A Canticle for Leibowitz" by Walter Miller.
#5. Arthur C. Clarke's "The City and the Stars".
There's a whole bunch of mentioned events that are not explored in the books and short stories so far. I guess some of them are even filmable. Chasm City or the Glitter Band would also be an interesting setting to borrow for a series.
If successful, they could make additional seasons of the subsequent books.
- Stanislaw Lem's "Tales of Pirx the Pilot"
- Clifford Symak's "City"
Gray-Death-Trilogy by William H. Keith, Jr. (Subset of the Battletech Series)