These are what I use:
Knife
http://www.cutleryandmore.com/details.asp?SKU=5198
Shears
http://www.cutleryandmore.com/details.asp?SKU=651
I use the knife for everything from killing to piecing, except for cutting off the head and neck. I use the shears for cutting off the head/neck and for cutting through the bones of the carcass after taking off the meat. The best part about the shears is that they come apart into two pieces, so they're extremely easy to clean.
We decided to buy some good knives after taking a Knife Skills class at Central Market and found out that our favorite knives (which whe brought to class) were worthless. One of the "skills" taught in the class was how to take apart a chicken (already eviscerated, of course!). We bought a set of 3 knives and a sharpening steel from the above site, and got the shears at CM (had a coupon).