Well I've been thinking of picking up a different 50mm as 35mm is sometimes a little too wide for me with street photography in London.
There's a lot of choice out there for a Nikon shooter - Nikkor's own f1.4 and f1.8, in G and D variants. Carl Zeiss has an f1.4 and f2 (funnily enough I'm not willing to stump up the cash that an Otus requires even though it's 55mm, Sigma f1.4. Using Nikon's F mount, you can even delve a little deeper into Nikkor's back catalogue with Ai-S, Ai, E and other variants if you're not afraid of manual focus. Then there's converted Leica R mounts as well - decisions decisions...
I managed to get a great price on something a little different though - a Nikkor 50mm f1.2 Ai-S. Now this is a lens with real character - possibly not to everyone's taste - which should be fantastic to shoot. Can't wait to get it delivered and try it out...