I'm not really much of a Sci-Fi/Fantasy fan (more of a mystery dood, myself), but I have been enjoying the following series (one of which is supposedly concluded and the other one is apparently about to)
Old Man's War's by John Scalzi - Think a more modern Starship Troopers with more sophisticated politics behind it. Should be done, there's 4 books in the sereis that I've read - Old Man's War, The Ghost Brigades, The Last Colony, Zoe's Tale. There's also a novella called the The Sagan Diary, but I couldn't bring myself to spend $13 for 100 pages that I'll read in an hour!
The Codex Alera Series by Jim Butcher (Starts with Furies of Calderon) - Imagine a world founded by a lost Roman legion where humans access magic via spirit incarnations called Furies. (What I think is the final book is about to be published in two weeks)
The Dresden Files by Jim Butcher - This is what restarted me looking at Fantasy/Sci-Fi recently. It's a series of books that deal with a modern day wizard in modern day Chicago. He acts like a PI, but gets entangled in the ongoing war between humanity and creatures from the NeverNever including the Fae and the Vampire courts, etc. Lots of fun.
And like I said I'm a big old mystery buff. Lvoe the damn things.
One series I'm working my way through right now is the Beekeeper's Apprentice series by Laurie R. King about a young woman becoming Sherlock Holmes apprentice in the years following his adventures chronicled by Watson.
Also, I find myself constantly returning to Raymond Chandler's works as well as the Travis McGee novels by John D. MacDonald.(Deep Blue Goodbye is the first of them) - Those novels are direct influences on the whole "Florida" genre of crime writers that exist today.