My two favorites are currently my M Leicas and my Rollei TLR. Both are silent and can be shot from the hip. Years ago, I used to have a Linhof 220 camera that took 6x7 negs. It was also great for quick street shots, especially if you like the vertical format.
I've used a Crown Graphic for street photography. But I've used 35mm and MF, too. Depends on what I'm after.
The best format for street photography is the one that works best for you, to get the results you want. If you want sharpness at large print sizes then I guess you'll be looking at MF. A lot of people have done great street work with TLRs.
Find out what works for you. Cheers, Paul.
I'd definitely start w 35mm and a wide-ish lens, burn lots of small film, see how you like the whole experience of street photography. I just recently got the bug (again), put up some of my older street work on my blog, stop by.
Say what you will, but I've actually had good luck using the Kiev 88 and Arsat 80mm. It seems that people aren't as weary around it for some reason and actually take interest in it. As a bonus the Arsat lens can be set to hyperfocal. Plus it was cheap enough that I don't have to be worried as I would be for carrying a more expensive camera around.
I would suggest Fujifilm GA645. It is much cheaper than a Leica, but the image quality is fantastic. The GA645 is an medium format equivalent of Konica Hexar 35. Very easy to use, great autofocus, lots of manual overrides. The only negative is that it is louder than a Leica, but this should not be a problem for city street shooting.
A modern Mamiya 6 or 7 is a great street camera. Large negs, QUIET as a leica shutter, decent metering, Rangefinder focusing. Capability of 220 film too allowing more shooting before reloading. Handles like a big 35mm SLR.
Go with whatever camera(s) you are most comfortable with.
I have thousands of "street" images in my files, most of which are tack sharp and very enlargable (I cull my files every few years and fuzzy generally goes to the trash), all shot on 35mm. An amazing amount of those on Kodachrome.
I use Nikons exclusively, not because they are any better than any other brand but because I've been shooting them on a daily basis since the 1980s and I can literally run them blindfolded in the dark.
BTW, an F4 or F5 with a 20, 24, or 28mm AF lens and the prism housing removed - allowing waist level operation - is a very discreet tool for crowded street situations.
Besides, my favorite street camera was the Yashica T4, just replaced with a Nikon 35TI, both loaded with 400 ISO B&W film or 200 ISO slide film.