I second Brandon Sanderson. He's pretty awesome. Elantris, Warbreaker, and The Way of Kings are good, Mistborn is incredible.
The Raksura series by Martha Wells- a shapeshifter who has never known another member of his species suddenly finds himself in the middle of the court politics of his kind. I like this series because the main character goes from a wary outcast loner to an important member of a society he knows nothing about in a very short period of time and has to adapt to the change very quickly.
The Coldfire Trilogy by C.S. Friedman- The trilogy starts out with the main characters seeming to be polar-opposites: one is a devout (self-righteous) if somewhat unorthodox priest and the other is considered by the priest's religion to be the most evil being alive. They both hate one another but are forced to work together to save humankind. Eventually, they go from being The White and The Black to being shades of gray. The development of their relationship is entertaining.
The Godspeaker Trilogy by Karen Miller. The main character of the first book, Hekat, starts life as a nameless, abused, and neglected child who was sold into slavery by her father. She goes from slave to warrior to wife of a great warlord to empress of a whole continent. And that's just the first book.
Codex Alera series by Jim Butcher. The main character, Tavi, is the only human in his world to be without a fury (basically an Elemental), and is treated with anything from pity to disdain. Then he gets the call and has to go out and save the world multiple times. Lots of character growth for him, but also for secondary characters.
I passionately second the recommendation for Martha Wells' Books of the Raksura. Not only does it satisfy your desire for deep, meaningful character development, it's also fantasy done proper! Not a damn bit of the setting bears any resemblance to Europe, or Earth for that matter. You shall find no such cliches as elves, dwarves, dragons, or humans in the setting of the Three Worlds! It's colorful, exotic, brimming with wonderful characters, and knowing nothing of your reading background I can nevertheless assure you it's like nothing you've ever read. The first book is The Cloud Roads, but be quick! It has recently gone out of print, so physical copies will be hard to come by. It's still available in digital formats, but it would be a shame to miss out completely, I assure you.
I feel that way about every single R. A. Salvatore book I've ever read.
However, if you want something with awesome character development and a better plot than "let's skewer some goblins/orcs!" I'd check out Brandon Sanderson's Mistborn series. He's become fairly well known for finishing Robert Jordan's Wheel of Time series, but I've only ever read his original work. I've only been reading fantasy for maybe five years, but his Mistborn books have become my favorites of any genre.
Just to give a little background on the story, it begins with a teenage, street urchin tomboy named Vin, who finds out she is a Mistborn (she can use the magic system employed in this universe) when she is rescued by a gang of thieves who plan on overthrowing the empire and freeing the majority slave class from their miserable life. There is political intrigue, badass fight scenes that are anything but repetitive/boring, a unique and well-developed magic system, and really interesting characters with a lot of growth and personality. I promise it is worth checking out.
Ah yeah, I've read him through Wheel of Time, but there he didn't have much control of the plot. He did some interesting things to existing characters, though. If there's politics involved that's a huge plus indeed. Worth checking out! Thanks