flies matter not, only presentation
I agree with your principle, but wouldn't go that far. Hmm, 5 is tough. Plus, you have the question of is this "if you had to pick only 5 flies, what would you pick", and "what are your favorites?" They are two different questions.
If forced to choose only 5, everyone is gonna pick generalist flies that can pull duty for different bugs, and they're gonna have a dry, a nymph, and a streamer for 3 of them. Mine would be:
1. Parachute Adams - brookie fly and works fine for most mayfly dry fly duty. Even caddis it's not bad for.
2. Black sculpin - my streamer of choice
3. Pheasant Tail - my nymph of choice, covers most species fine. Also float it in the film, and its a great emerger.
4. Spent wing trico - Cut the tail off and its a midge! Clip the wings and it's an ant!
5. Glo bug - need somethin for the steelies and stockers.
Those aren't necessarily my favorites. For instance, I'm not super fond of subsurface work, I only do it because it works and often it's all that will work. My favorite times on the stream are during the major hatches, and thus, what I use then would be my "favorites". So I'd probably pick 5 dry flies, though keep in mind, if this is all I carried I'd be pretty much SOL for 80% of my fishing time.
1. Sulpher comparadun
2. Cut wing thorax BWO
3. March Brown catskill tie
4. Green Drake.
5. yeah, the Adams Parachute.