Terrestrials: I learned early on that terrestrials are huge portion of a trouts diet and for a major portion of the year. You can fish this fly from June through November. Last year Sam and I landed some nice browns that were preping for spawn with this fly. It doesn't look like much, just some black foam and rubber legs, with yellow foam on top for visibility.
Hoppers: That first fly is my go-to terrestrial, but hoppers are good to. This one is real easy to tie, dub a body, lay some foam over it, tie in some legs and top it with a turkey feather. I will also fish some ants, but hoppers and the cricket-like fly above will do the job when fish are hiding in bunkers and looking up.
Black Caddis: I hit the black caddis hatch last year and it was really good, not great, but good. This year I'll know what I'm in for, and this fly will get abused.
Blue-winged olive: The most consistent hatches in the driftless ares the BWO's and the Hendricksons in the spring. This fly will work for both. This is the best BWO (and all around mayfly) pattern I have found. Mallard flank for a tail, dub a body and lay a clump of deer hair on top. I trim the butts of the deer hair long for a wing pad, it helps the fly float better. -This is a sweet pattern.
Midges: I'm a terrible midge fisherman, but it isn't because of my flies, its becasue of my presentation. This fly is really all you need, the griffith's gnat. If I can get this fly to float well, and I can see it, I usually will get fish during a midge hatch.
When the fish are feeding on the surface, the above flies should do the trick, the 98% of the time that they aren't looking up, go with these:
Streamers: Big flies=big fish. This is a mini-clouser tied with rabbit strips. One on top and one on bottom, tie in a bit of flash and hit the water.
scuds: Otherwise known as amphipods, these critters eat aquatic vegetation. A big rain event will flush them down river and they will get the attention of big fish.
Hare's ear nymph: You can fish all sorts of nymphs and do well, but this one is really all you need, I think.
Thread midges: Trial your nymph with one of these...Simple pattern, consistent results.
The one thing that my favorite flies have in common is that they are all really easy to tie and don't have a lot of materials. I like to sit down and crank them out in a hurry, they don't need to look pretty, just proportioned well.
What are your favorites? If you could have just one of the above, which would it be? What would you add to the list?