In general, the better kitchen knives are forged metal rather than stamped, which means they are made from molten metal and are heavier than their cheaper cousins. A good handle is a must as well.
So just who does Consumer Reports think makes the best knives?  The May 2009 report shows that forged steel knives win again.   CR has an online report explaining what all the different knives are best used for too.
The anatomy of a kitchen knife
Image: Consumer Reports online

This would be a wicked fine knife to add to your collection!  The Mezzaluna is 5 inches wide and comes with an 8 inch board.
The classic half-moon shape doubles up for even faster chopping. Two-handled, double-bladed design creates a smooth, stable rocking motion for prepping foods right in the hollow of the square beechwood board.

In a game of pretend gladiators with his police officer father, 11-year-old Conor Johnson was stabbed in the heart and died four short hours later. His mother, Sharon Johnson, claimed that his medical care was inadequate with no specialist cardio-thoracic surgeons available.
Ian Johnson, 40, told a coroner’s inquest how the four-inch stainless steel knife “slipped from my grasp” during some rough and tumble play with his son, Conor, 11, while he prepared dinner. The knife pierced the left ventricle of Conor’s heart.
What a horrible thing to happen to all of them.

Times Online, July 7, 2006