Many are heirloom apples that have survived for 100 or more years with names like Black Twig, King David, Hog Sweet, and Hubbardston Nonesuch, But I also grafted some of the newer disease resistant varieties such as Florina Querina, Galarina, Enterprise, and NY 35 Bonkers.
I'm also having good luck with my limb grafts. These are grafts I've made to an existing tree mostly Antonovka (Russian) seedling trees, a long lived, cold hardy tree that is slow to produce fruit, that I planted 6 to 8 years ago. I'm hoping that in 2 or 3 years these grafted limbs will be producing apples.
With insects, diseases, and the weather all trying to foil your carefully laid plans it helps be an optimist when it comes to planting fruit trees.