I use both focal lengths, but use more frequently a 50mm lens than a 35mm lens. When I want to include people in my travel photos, I prefer the 35mm focal length,and when I want documentation of people's faces, I prefer the 50mm focal length. In my last trip, I had the 28mm-35mm-50mm lenses, but the 28mm lost out and stayed in the camera bag. It was too wide for my needs. Typically, I have faster 50mm lenses than 35mm lenses, and this also affects which lens I use at available light.
The old style chrome Canon 35mm/2.8 brought me back to 35mm lenses since it looks super cool on LTM bodies and it provides nice optical performance too. Sometimes, it is the coolness of a lens that is the decisive factor here.
The 35mm focal length is a normal lens that is slightly wide. Hence, it is perfect for indoor photos. Distortion is not visible, and you get a wide angle lens.
On the other hand ... the 50mm lens is King.
As you see, it is a toss-up for me.
Raid