A greater challenge would be avoiding prepositions. :)

My taste in SF runs from Golden age classics like the Early Robert Heinlein (I think everyone should read “Door Into Summer”). I especially like the Heinlein Juveniles.

I like the modern CyberPunk novels like Gibson. I like Shirley’s Eclipse books. I like Vernor Vinge’s books. Read Vinge’s True Names and other stories.

Asimov is good, but dry. I like Clarke’s short stories better than his novels.

The later Golden Age has people like Anderson, Pohl, Harry Harrison, and Blish,

The best, though, will always be Ray Bradbury.

I am a big fan of Leiber’s Gray Mouser stories, although they are not novels.

I like Poul Anderson’s SF books. He also wrote a few fantasy books. You should try Three Hears and Three Lions by Anderson.

Of course, there is Conan. Read the Howard books. I assure you that there are no characters even remotely similar to Arnold.

I reread Edgar Rice Burrough’s Mars books every few years. They are fantasy, even if they take place on Mars.

Andre Norton’s Witch World series started out as one stand-alone book and slowly grew so you can read the first few Witch World books without having to read sever 10 pound sequels.

Fantasy books before J.R.R. Tolkien were usually a single novel and under 100K words, so look for good fantasy from the 40s 50s and 60s.

But I was specifically asking about the more recent stuff, especially sci-fi. Like Iain M. Banks Culture series. I go to the bookshop, and, once you get past the heady influx of emo teen vampire crap, there and a lot of books that I just don’t know if it’s worth my while even starting, especially if it’s a series.

Depends on what kind of sci-fi/fantasy you like. I would add some of my favorites:

anything by A.C.Clarke – mostly technological or “philosophical” sci-fi
Frank Herbert(+ his son and others) – anything from Dune universe(I really recommend to read it from it’s very beginning(Butlerian Djihad is the first book in the series)
Isaac Asimov – Foundation
Dune and Foundation are multi-part novels so don’t worry about the length :-)
W.Gibson – Neuromancer, Johny Mnemonic – Gibson is considered father of cyberpunk, very interesting reading but for someone it may be too difficult

fantasy:
If you only read LOTR or Hobbit from Tolkien’s books about Middle-earth, there’s more:
Silmarillion – myths and legends of Middle-earth and events preceding and thus explaining some things and references in LOTR
The Book of Unfinished Tales – collection of mostly unfinished works on Middle-earth – many people don’t know there are two parts
Hurin’s children – the longest of the “unfinished tales” finally completed. It was published only recently by his son.

R.E.Feist – Riftwar Cycle(probably most known book is Betrayal at Krondor)
A.Szapkowski – The Witcher saga – sometimes incorporates even “naturalistic” approach to fantasy(btw this story was made into quite good RPG PC game just recently)

off course there are many more…