Nikkor 50mm f/1.2

General
Very fast normal lens. Is the absence of auto-focus a problem?

Pros/Cons
+ very fast, excellent for low light or subject isolation
+ superb image quality, incredibly sharp and beautiful bokeh
+ small, light to carry

- manual focus and f/1.2 will drive you insane. Even static objects can be difficult to focus on
- expensive (with the same money more or less you can get a brand new AF-S 50mm f/1.4)
- large front element susceptible to damage/dirt

Gorgeous to look at, that's for sure

And its bokeh is simply otherworldly

Intended Users
Great for:

• photographers who are after abstract, blurry, creamy bokeh and subjects
• artists who don't care too much about perfect control
• low light

Not for:

• anything moving
• those who don't intend using it at f/1.2 - get the much cheaper AF 50mm f/1.8 instead
• impatient people who don't want to struggle with manual focus

Final Verdict
A superlative lens, to be sure. Image quality is incredible, bokeh is phenomenal, optical and mechanical quality are matchless. But this is a very special lens. The lack of auto-focus, paired with the extremely shallow depth of field of the f/1.2 aperture, will drive you insane if you're impatient. You must really, really, REALLY ask yourself whether it's worth to spend so much money for a lens like that - with the same money, you can get an autofocus f/1.4 lens. It's not as good, not as fast, and not as sturdy. But it might save you a lot of frustration.