Another voice for the SB-800. I have five of them and use them with both film and Nikon DSLRs. Compared to the SB-600, you get about 1/2 stop more maximum power, a slightly nicer control layout and a built-in SU-4 slave capability, which means if you later want to do portraits with off-camera flash (SO much nicer than on-camera for good portraits) you can use any old on-camera flash as a fill light and trigger and optically trigger the SB-800 as a main flash. The SB-800 has aperture operation for backward compatibility with manual cameras ( i.e. you tell the flash the aperture you are using, and it senses the reflected flash light with its own sensor, not through the lens, and cuts it off when exposure is adequate, like 1970s auto flashes do). I'm not sure if the SB-600 has this capability.