Again, depending on your cooking style, some extra pieces can be:
An auxiliary blade - a versatile tool for handling smaller parts.
A meat cleaver - to cut chicken, ribs, and chunks.
A vegetable chopper - for chopping and slicing vegetables and herbs (or as a chef's knife).
A boning knife - to remove meat from chicken, ham or roast meat.
A cutting knife - for cutting thin pieces of roast meat, turkey, chicken, pork, etc.
Sharpening steel - to keep the edges of your knives accurate and sharp.