Three solid choices and an honorable mention
I am a huge George RR Martin fan although A Feast for Crows was sort of a let down for me. If you are not a fan of of the magical fantasy genre and enjoy gritty realism then you will probably enjoy the series. The greatest thing about the series is that there are no defined "bad" guys, only those that are doing what is in their best interests to gain power or save their own skin. Tyrion is by far my favorite character :cool:. Oh and need we mention the HBO series coming out that will follow the books...it will be fun to see that adaptation. Also, there are only 7 books planned in the series to date which is much better than 8 as Martin takes years and years to release books.
I also enjoyed The Dark Tower series by Stephen King. This is a long series consisting of 7 books which took King about 30 years to finish. It follows Roland, a gunslinger, and his ka-tet through thick and thin in his quest for the dark tower. The first book is not very good (in my opinion) so don't give up there. The series takes a wild spin at the end of the fourth book and ends very nicely at the conclusion (although everyone doesn't agree). Also the creator of Lost has bought the rights of the series to adapt to a tv series or movie (for $19 dollars :D).
The last series I would suggest is The First Law trilogy by Joe Abercrombie. This is similar to Martin's series as there is a lot of twists, turns, and misfortunes that follow the main characters and there are no "good" or "bad" guys. It follows the same style also, in that each chapter is from the point of view of a different main character. So if you are looking for something new give it a try. It's still not quite to Martin's level as it is a debut series and his writing isn't quite refined yet. He just released another stand alone novel falling in the same world as the trilogy with another planned in the next couple years.
Honorable Mention: R. Scott Bakker's The Prince of Nothing <--great read if you are into philosophy. It's no picnic but is very interesting at times :D. First 3 books are out with 4-6 to follow.
Thanks for reading part 1 of my trilogy ;)