Thinking about the focal lengths I prefer when walking around, I like:
24-25mm
28mm
35mm
50mm
My most used (translation: easiest) camera/focal length for street is the smallest wide angle camera/lens I can get, which in my case is 24mm with the Sony RX0 or Panasonic LX10. Before that, it was approximately 22mm with the Panasonic LX7 in 16:9 ratio.
I also like working with a 50 at the same time, so I can swap between the two focal lengths. For me, the 50 is the tiny Olympus 25/1.8 on the Panasonic GM1 or GX85, or the Leica M9 with 50 Cron. I often enjoy using the Sigma DP1 (28mm) with the M9 + 50, the Sigma around my neck and the M9 across my body. Another combination I enjoy is the Panasonic GH4 + Olympus 25/1.8 across my body and the Sony RX0 on my wrist. The Sony is light enough to dangle from my wrist if I switch to the Panasonic.
A 24-70 zoom lens would cover these focal lengths easily, but apart from the Panasonic LX10, any larger sensor option would be much bigger than a tiny prime and a pocket camera. The smallest way out of it would be the Panasonic 12-31mm collapsible pancake on a small m43 body, but the image quality isn't as good as primes, nor is depth of field shallow enough for my liking.
I have had enjoyable times shooting with the Canon 30D and 17-55, and the 5D Mark II with 24-105, but when compared with small cameras and tiny lenses, I much prefer the latter for size and weight.