I'll throw in my $.02 on this topic. When I'm fishing the streams in the northwoods, the flies I will NEVER leave home without are:
Nymphs:
- Pheasant Tail
- Copper John (red & copper)
- Pink Squirrel
- Bead Head Hares Ear
- Brassie
Dries:
- Adams (sz 16)
- Elk Hair Caddis (sz 14 & 16 in both tan and gray)
- Blue Wing Olive
- Hoppers (usually tan or green bellies)
- Beetles & Ants (Do not overlook this. Some spring and summer months I will fish these, and only these all day long)
Streamers:
- Black Wolly Bugger (Sz 8, I like them flashy)
- Olive Wolly Bugger (Same as above)
- Crawdads
If you want to pm me the streams you tend to fish the most, I can probably help narrow down the flies a bit more for you.