Big Game: Deer, Elk, and an occasional Moose.
A good 4" or 5" blade is all I've ever needed.
Other than that, mostly birds (pheasant, grouse, duck) and fish (trout and Salmon).
I prefer a fixed blade because it's stronger (better leverage) and because fixed blades are easier to clean (less cracks to take care of).
You've got some beautiful blades available . . .