MAINE - Life in the Slow Lane
If I was told to use only one fly it would be the Muddler Minnow. But I am very pathial to the pheasent tail nymph, size 16 or smaller.
Lee
Very good choices, I have to say in late summer the hopper is king, early spring pheasent tail nymphs and emergers. Fall Caddis is a good one, Winter Midges work well . But my go to fly when all else fails a soft hackle (partrigde) Wet Fly Is a Killer.
Hi Dave
My favorite fly is a brown hackled buck bug with a natural
grey deer hair body...Size 6 and 8 for salmon and in size 8 and 10
for trout.. It can be fished wet or dry..I prefer to hold it under water
and squeeze the air out of and fish it wet.
Stephen
Mickey Finn hands down is the go to fly when the chips are down!!! (for trout)
My dad used to troll his favorite was the Old Grey Ghost.
I have a few ....
Flash back pheasant tail
Soft hackle - hares ear size 3906b 12
and a Slumpbuster tied Clearwater style
Both good flies Jake and Stephen. I have gone to soft hackle flies more and more and find them very effective.
Dave V
I would have to say the Copper John is my go to fly around here. But I am also a convert to a slumpbuster as well. 
What is your favorite fly ? Do you have a secret weapon when all else fails ?
Eventually, all things merge into one, and a river runs through it. The river was
cut by the world's great flood and runs over rocks from the basement of time.
On some of the rocks are timeless raindrops. Under the rocks are the words,
and some of the words are theirs.