This guy :
http://www.peterfhamilton.co.uk/
Space opera typish stuff.
I'd recommend starting out with the Commonwealth universe, and starting with the first two books in it :Pandoras star, and judas unchained. (missspent youth is more of an optional fluff / background story book and isn't really required to read the series).
Hes probably one of the best authors i've had the pleasure of reading anything by - and the last book in that series isnt out yet(scheduled for september 2010)
I assume you have already read The Hitch Hikers Guide To The Galaxy - if not, you better get on it
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Enders game is also pretty good, thought its an old book, unsure of the author. And also, however lame the movie was, see if you can pick up a copy of Starship troopers. Not sure i've ever seen a move shamelessly destroying a great story as that one did. The book is excellent however, wouldn't surprise me if games workshop got a bit of inspiration for space marines from that one.