Filet knife, Kershaw hands down. These things are razor sharp, stay sharp and come in 2 versions that I know of, standred fixed length blade, and adjustable length. I have both they ROCK

. They are both too big for small pan fish though, thats where the rapala comes in.
So far as kitchen knives, the best ones rust, the German ones are good too, all comes down to how much $$$$$$$$$$ do you want to spend, stay away from flimsy thin blades and riveted handles if possible IMO, make sure you get a sharpening and honing steel as well, with some practice, patience and care, you'll touch up an edge in no time, reguardless of brand.