I have cleaned literally thousands of squirrels, coons, and quail, I have two favorite knives for the job a JA Henckels 3" paring knife with an edge that gillette would be proud of. I also have an old stag handle stockman that has seen a lot of use, I like the spey blade for coons.
I have never seen one of those woodswalkers before the other day but you can bet I am going to get one, it looks a whole lot like my henckels.:thumbup: Chris
EDIT: IMO guthooks are hideous abominations and have no place on a knife.
I reread your post and you also asked about about fishing, that makes things a bit trickier, if you are talking about panfish and trout, the knives I named will work fine, if you are talking about filleting a northern or striper, you got problems, there is no all around knife there is always a compromise.