C++ complete reference if you don't have any knowledge at all about C. C++ Primer if you have tried your hands at C... Both books are great. See amazon for readers ratings of these books. They are 4.5/5
Aaarrghhh... you people dug up an OLD thread. I am using Practical C++ from O'Reily and Professional C++ from Wrox. Both books are great for improving your coding style. NOT FOR LEARNING. They are too advanced if you want to learn C++. Use the books referred above in that case.