It would be hard to pin it down to just one fly but the elk hair caddis is right at the top on my list.I live within a half hour drive of one of the best trout rivers in North America the Bow River in Alberta,Canada.I Spent alot of my youth learning to flyfish on this river,but inthe last few years my new love is fishing from a float tube on small lakes in and around the area.I do enjoy all types of flyfishing dries,nymphs and streamers.I tie my own and find that almost as enjoyable as fishing them.