When I first began trout fishing I did not like to fish with nymph's because I was always losing flies and getting hung up and seemed to be tying on more nymphs than fishing. But I went to a seminar that was taught by the well known famous nymph fisher Joe Humphries and saw how productive it was for him. I changed my attitude and learned to become a better nymph fisher. While I can't say these should be etched in stone as the top ten, they are very close between most obsessive trout fishers as myself. You may see these tied with a little color variation from fly shop to fly shop but here they are:
1. Gold Ribbed Hare's Ear
2. Gray Nymph
3. Zug Bug
4. Black Midge Pupa
6. Kaufmann's Stone
7. Scud
8. Beaver
9. American March Brown
10. Prince Nymph
And one for good measure Copper John