Mine would have to be my 5weight Hardy fly rod matched with Abu Garcia reel with floating line and 4lb Maxima leader, I love that outfit caught my biggest rainbow of 2.4kgs on it, although I think my leader was 6lb at the time...
My favourite flies, of which I have many, include: RAB, Yellow Humpey, DDD, Walkers Killer, Zulu, GRHE, Buzzer imitations and the Black Woolly Bugger with bead in front... this is a pic of the outfit below: