I can wholeheartedly recommend Simmons, and particularly the Hyperion Cantos and Illium series. Both are unreservedly brilliant, unusual sci-fi. Prepare to become more familiar with Shakespear, Proust and Keats (Simmons is famous for his intertext)!
Both series (set in separate universes, unrelated) are epic, exceptionally well written, and actually chock filled with action for something with cerebral leanings.
I picked these up on a similiar hunch after becoming utterly frustrated at most of the recent fantasy I'd read (latest Jordan, Terry Goodkind etc) for being unbearably lethargic when it comes to plot advancement. Simmons is the diametric opposite - the plot moves forward with lightning speed.
Anyway, can't recommend it enough. I'm not massively well read in the sci-fi genre, but I'd rank Simmons up there.