I used to shoot half frame, 135, 6x6, 4x5, and 5x7 but since going digital with a Leica Monochrom and loving it I am cutting film photography down to half frame with Olympus Pen FV and 6x6 Rolleiflex. I am undecided on large format.
Just got an 11x14, so I guess I'm officially a ULF shooter now. As well as 8x10, whole-plate, 5x7, 4x5, 2-1/4 x 3-1/4, 6x6cm, 6x4.5cm, 40x28mm (828 film), 36x24mm, and 18x24mm. It's been a long strange trip.