For the year 2011 ...
... I did very well with only eight or so dry fly patterns and a couple nymph patterns for well over one hundred days fishing moving water in the Northern Rockies.
I expect to do about the same next year - FEB patterns for skwala, salmonfly, golden stone / hopper, and October caddis plus a couple small caddis, a small BWO, and a Griffith Gnat for dries from March through November. Several colors and sizes of rubber legs stonefly nymphs and a couple sizes of soft hackled pheasant tail nymphs will get me through the rest of the year.
Several colors of antron yarn, a couple colors of closed cell foam, two or three variations of MFC centipede legs, and a patch or two of humpy deer hair will do for the big dries, add some BWO and caddis dubbing, CDL for BWO tailing and peacock herl for the gnats, and a couple sizes of grizzly hackle for the small dries.
Nonlead weight, a couple medium cheniles, and rubber leg material for the big nymphs and some pheasant tails, copper wire ribbing, the peacock herl, and grizzly hen will do for the small nymphs.
Just today, I "started over." I boxed up a bunch of materials that I had acquired since the last time I "started over" a few years ago that I haven't used hardly at all and don't expect to use and sent them off to BB member MTWFF in NE Montana to use in his fly tying classes for the Boy Scouts.
P.S. Realizing, of course, that I might get a little crazy and want to do some coppery john nymphs or some drake or PMD dries or something equally exotic, I did hold onto a couple extra spools of ultrawire and an extra pack or two of dubbing. None of that UV stuff, though.
The fish are always right.