I am looking for a sci fi book that makes you think a little bit. Something similar to 1984 or enders game but maybe less widely known. Any suggestions?

Discworld by Terry Pratchett
Dune by Frank Herbert
Foundation series by Isaac Asimov
Brave New World by Aldous Huxley
Hitchhiker's Guide To The Galaxy by Douglas Adams

The Illustrated Man - Short story compilation, I found quite good.

2001

You should check out Blindsight by Peter Watts, it's fucking awesome

lol most sci-fi books make you think

read anything by
Philip K Dick
or
Peter Hamilton

hope enders game was different from the film, i liked it but you'd have to have a pretty undeveloped intellect to think about anything other than bugs and floating in space

Stanislew Lem - Solaris

Anything from the Strugatskis or Philip K Dick



also these (not a fan of pratchett tho..)

Especially Brave New World, read that shit lots of times.

I reallllyy enjoyed this read.

http://en.wikipedia.org/wiki/The_Futurological_Congress

If you enjoyed Enders Game I suggest you continue reading the others books in the Ender series, there's also the Shadow Saga which tells many of the same stories but from Bean's perspective.

I'll add to this that any of the big 3 (Asimov, Clarke, and Heinlein), as well as some other great science fiction writers would leave the reader thinking. Philip k dick has written a good many as well.

Otherworld series