The Pheasant Tail is one of those nymphs that has stood the test of time.  The standard version's legs and wingcase always dissapointed me in that they were the first thing to come apart.  Turns out removing them makes the fly infinately more durable.  Added bonus, the sleek profile sinks a little quicker.  The red thread collar just felt right...and the fish agree.  This has been in my regular rotation for the last 7-8 years.