chef's knife for cutting chicken, or butcher's
If you're just separating a chicken into pieces, you don't need to cut through any bone, and a chef's knife or a boning knife will work fine. You need to aim for the joints in between the bones, and cut the softer connective tissue.

If you're actually trying to hack legs and thighs into pieces (some indian curries, stocks, and other preparations do well with splitting bones), then you need a heavy duty meat cleaver (note: a "chinese cleaver" has a thin blade, and is unsuitable to cutting through bones). A chef's knife would work, but can dent or chip the blade of your expensive Global knife.