Rokinon is very, very good. Nikon G is apparently a bit better, but look at that price ($1600 or something!). And then you need a special adapter to change aperture.
Canon L might be the way to go if you have the money. But the Rokinon is excellent, on par with the best Canon lenses only it's manual everything.
Old AI-S Nikkor is garbage optically (technically) and loaded with coma and spherical aberration but it gives a cool "look" and is tiny. For the right projects I adore it.
I have the 35 f2 AIS and its a wonderful little lens for quick video work and if you want to go light.. I only use the 35 1.4 cine (which I rent btw) when I rig up my D800 , its a beautiful lens too. Can't go wrong with any of the two.