Where to Start With: Iain Banks (theguardian.com)

I think Banks is quite unique in his presentation of a space-faring civilization and I love him for it. If you want to start with the Culture novels you can't go wrong with either Consider Phlebas (more of an outside look and a bit of critique of the Culture) or Player of Games (the Culture is much more fleshed out).

If it's (amazing) sci-fi you want, he published under "Iain M. Banks". As "Iain Banks" he wrote (amazing) literary fiction.