I have any number of SLR and rangefinder cameras, and all of them can be used for street photography. The cameras I usually carry are either a Leica M4, or Olympus OM.
Recently I picked up some small Yashica rangefinder cameras, one is an Electro 35 CC, and the other is the identical Electro 35 CCN. These little cameras are incredible, they are smaller than my M4, much quieter, and far faster to use. The exposure system is aperture priority automatic, so all you need to is set your aperture, focus, and shoot. What's more, they come with a 35mm 1.8 lens, which offers a very convenient field of view, while having very good speed in low light. The only thing which limits these cameras is a rather limited ISO setting selection, and a top shutter speed of 1/250th. But for evenings or indoors they are excellent, the CC has a maximum exposure time of 15 seconds, while the CCN has a maximum exposure time of 8 seconds.
These cameras are an improvement over the regular Yashica electros in that they have the exposure indicators located inside the viewfinder as opposed to being on top of the camera body, so you can see the lights without taking your eye and camera off the subject.
Unfortunately, these cameras are rather rare and pricey, but there are a few listed on eBay now.
Another recent purchase of mine is the old Olympus XA rangefinder. This is the tiniest camera which I have, and I'm looking forward to putting some film through it to see how it works.