Nikkor 50mm f1.8 or 35mm f1.8?

For everyday photography. Which would you recommend better? And which focuses faster in lo light?

The 35mm will probably focus faster in low light if it's the newer lens. I personally prefer the 50mm over the 35 for everyday photos, but it depends on how much of the scene you want to photograph. If you usually photograph more than one or two people, you'll definitely want to go with the 35mm. If you enjoy portraits, go for the 50mm.

Hmm.

The 50 mm on a dSLR is a great portrait lens.

Since the 35 mm f/1.8 is a AF-S lens, it will certainly focus much quicker than the AF 50 mm f/1.8.

If your Nikon dSLR is an entry level camera, then ONLY the 35 mm can auto-focus.

Personally I rarely use the equivalent of a "normal" lens for anything. My Nikkor 50 mm f/1.4 and Leitz 50 mm f/2 are rarely used on my 35 mm cameras. I cover those focal lengths usually using a relatively fast f/2.8 mm zoom lens.

A note on focusing in low light. If there's NOT enough light, the camera will NOT auto-focus without the camera auto-focus assist light being used.

What you have to ask yourself, which focal length do you need in your day to day shooting? That is the lens you will want to buy. With the amazing low noise at high ISO's, fast lenses are not nearly as important as they were when we were limited by film speeds of under 1600 (black and white) sensor speeds of 800 because technology just wasn't available yet

Here is a shot using an aging Nikon D300 @ 3200 ISO. As you can see, a f/2.8 lens is fast enough under low light conditions.

I have both and I find the 35mm f/1.8 af-s focuses faster. When it comes to low-light, I use the 35mm most often.

Here's some galleries I took where the closer shots were mostly taken with the 35mm lens on my D300.
http://www.sportspagemagazine.com/content/bb/mp-bb/g-mp-bb/sacramento-kings-99-vs-los-angeles-lakers.shtml?39321
http://www.sportspagemagazine.com/content/bb/mp-bb/g-mp-bb/sacramento-kings-104-vs-cleveland-cavaliers-117.shtml?37495

It's a matter of preference. On a crop sensor dSLR, the 35 is nearer to normal human eyes angle of view. On a full-frame dSLR, it's the 50mm that's normal. To focus faster in low light, set the camera to manual focus and do the focusing yourself. The wider angle lens will have deeper DOF under equal aperture sizes so getting objects into focus will be relatively easier.

For everyday photography, the 35mm f/1.8 as its focal length is closer to a 50mm equivalent on a APS-crop sensor camera (remember you have to times the focal length of the lens by 1.5 to get the equivalent). Therefore, the 35mm lens is neither telephoto or wide angle, which makes it just about ideal for many subjects. The 50mm on the other hand is a bit telephoto, which will limit your choices if your thinking of capturing wide-angle scenes (though the 35mm is far from ideal either).

As for autofocus, it depends on your camera body. Because the 50mm f/1.8 is not an AFS lens, its autofocus speed depends on the body you mount it on. On a professional body such as the Nikon D300s or D3, it should be blazing fast, but on a entry-level camera like the D5000, it won't autofocus at all. The 35mm f/1.8 is focuses fairly fast on any body, but don't expect it to be super fast (its about on par with a 18-55mm lens, maybe a bit faster).

Take your zoom, set it on 35mm and put a small piece of maskng tape on it to remind you not to zoom. Walk around with it for a few hours. Now do the same at 50. See which one you prefer.