I'm currently reading, and maybe recommending:
Hal Clement - Writes hard sci-fi about extreme environments. I liked Mission of Gravity. Voltaire sort of wrote a story on this theme btw., (Micromégas), but I haven't read it.
Bob Shaw - I like his Ragged Astronauts setting (I've yet to come by The Wooden Spaceships). I liked Orbitsville because I'm a sucker for big dumb ancient objects.
Lucian - wrote a fantasy parody (and/or criticism) called True History, taking the monster stuff to the extreme, turning it into Epic sci-fi in an attempt to top previous writers. His writing there is very reporter'y. Heroes did this, then this, giant creatures appear, so many died, then they were off again. It's probably part of the parody style. Unfortunately the humor is mostly confined to this one plane and gets a bit tiresome (again, it might have been his point). Reminded me of StarCrash (movie) where a buncha stuff just happens.
Stapledon was already mentioned. I like C.D. Simak (economics) too, and P.K. Dick (layers).
I read 4 of Banks' culture books while laying sick. The wrap-up endings tend to leave me a little dissatisfied, somehow, but the ride is fun. Working on Feersum ennjim now.
Jamen jag tror att han skäms, och har gömt sig. Vårt universum det är en av dom otaliga spermasatser som Herren i sin självhärliga ensamhet har runkat fram för å besudla intet.