Yep, Banks is awesome. The Algebraist is excellent, but takes 200 pages to get going.
Now then. I have a hot, hot tip for you. Read Roadside Picnic by Boris and Arkady Strugatsky. It's phenomenal and intelligent Sci-fi. The Strugatsky brothers are as good as Asimov / Clarke / Banks.
You can find the text file (legally) here.
http://www.rusf.ru/abs/english/index.htm
For those that love Bank's Culture novels, try to find Hard to be a God. I'm not aware of an ebook and the printed version isn't cheap (I found one for 50 cents!). Bank could have based the Culture on this, though I'm not suggesting that he actually did.