I'm assuming you are including nymphs as I seem to do well on various river trout with a gold bead headed black wooly bugger most of the time while fighting the Wyoming wind. I try to limit my total fly selection to a dozen or so but this usually increases both in type and size throughout the year.

i like a size 6 mickey finn on all the trout streams and rivers. Larger ones also slay atlantic salmon in quebec

Kaufmann stimulators on wild brookies.

I have a couple, my early season seek and destroy is a 1/2 length Moby Dick fished as a dry or wet or streamer, and then I switch to a White or Grey Wulff in size 4 for good dry fly action as my summertime seek and destroy fly. In the fall, I go to the Cinamon Flying Ant in a size 14, or switch back to the Moby Dick again.

Black and silver spratley or a mudler minnow. Caught some nice rainbows on these two.

Black beadhead krystal bugger. unstopable