Everyone will have their favourites but a fly that was new to me called Chip's Northern Magic was my go to fly at Cree Lake. Easy to tie with just two materials although I did add some NMF Titan Dubbing called UV Black Mirror and eyes to some of the flies.
It was easy to cast and the pike were all over it for some reason.
I like articulated flies or flies with wiggle tails as well. Great action in the water!
Take a look at this Orvis article on top 10 pike flies. There are so many excellent flies for pike. This is an excellent starting spot!