So I've started shooting a little bit of medium format film, and now I'm having a little bit of trouble with the fact that I know nothing about the film itself. I'm using an old Kodak 620 foldout and the moment, and I've shot a couple rolls of Fujicolor Reala and Superia, but there's no way I can really tell anything about the quality of the film, because the IQ out of the camera is just too shoddy to judge (I'm still battling leaky bellows).
That being said, I'm also looking into getting myself a Bronica, for fun and outdoor strobe work, which means I'll hopefully be actually using 120 film to its full potential. So, what's the best to buy? I remember hearing a lot about how awesome fujichrome velvia is supposed to be, which reminds me, how does slide film stack up against negative? I'm thinking I may as well just go to slide, since with the new camera I'll actually be metering shots, and less likely to horrifically overexpose. But anyways, I digress: what's your favorite film, and why? I'm open to any type of color film (sorry, black and white is more expensive to process, so I'm not gonna bother with it), as long as it's available in 120 rolls...

