When I was living out west in Idaho and Montana--I'd keep trout as long as I could cook it and eat it right then and there. Yummy! But now I release everything as I do not trust the water.
LOL we are a bit on opposite ends.. I keep sunfish,bluegills, crappie etc(as long as they are not tiny. (good eats)It depends what I catch. Bluegill and most other sunfish I rarely keep. Any bass big enough to get decent fillets off is a keeper. All legal walleyes are keepers. Big perch are excellent eating. Trout are always kept because they are plentiful in the fall and if they are not big enough for me to eat they make excellent crab bait the next summer. Also will keep any catfish over 12 inches. When it comes to salmon, if it isnt a baby it is a keeper.