For my personal work, which is mostly street photography, always primes. I like their small size and fast speed.
My favourite two lenses for street work are a 28mm-e (Fuji XF 18mm f2 on my X-Pro1) and a 50mm-e (Zeiss Touit 32mm f1.8). Sometimes I carry a 90mm-e (60mm), but more often than not, I leave it at home.
Sometimes I still use an old Leica M3, and on that, I use a Zeiss ZM 28mm Biogon.
My paid work is a different matter though. In studio, it's all Canon L zooms. When I do architectural photography, my go-to lens is the Fuji XF 10-24mm (about a 15 to 35mm-e). It's only a f4, but that's irrelevant as I use its optimum f stop of f8 most of the time. Zooms allow me to frame up and crop my shots quickly, to my client's exact specifications.