Right now, four. Two black F2AS bodies, a black F FTn, and a chrome Nikomat FTn. The most I've owned, all at once, would've been 13, back in January 2006. Had a chrome early F with waistlevel, two black F2A's, an F3HP, F3P, F4s, two Nikkormat FT2's, two FM's, two FM2n's, and a black Nikomat FTn that was used as a donor for one of the FT2's.
Over the years, I've owned around 155 Nikon bodies, starting out with a chrome Nikomat FTn that my dad gave me for doing chores around the house. The explosion of Nikon bodies didn't occur until January 2005, when prices of film gear plummeted.