Any of my 2 liter bottles work (I usually use sprite), my smaller club soda bottles work (generic store brand) smaller soda bottles (12 oz). Haven't had an issue with the threads. I do seem to have an issue with the o-ring, but I tend to put a layer of teflon tape over it and it's fine for a number of uses.
Secondary: GF Czech Lager
Waiting to be kegged, Italian Primitivo
Kegged&Ready: GF Orange&Coriander, GF Honey Lager, GF chocolate ale, GF English ale, Island mist (zinfandel), Island mist (cbry malbec).
Bottled: Infected Mead, Dry Hard ciders, Accidental Sorghumwine, various unnamed.