I'm currently using a set of Vintage Nikkors (except for a Sigma XQ 18mm f3.2 because finding a 18mm nikkor in good condition is pretty rare).
If they are in good condition (Focus is smooth, no oil on aperture blades, aperture is smooth, no scratches, no fungus on the elements) the image they provide is excellent, and make for a great start to a lens kit (since Nikon has kept essentially the same mount since the 60s) since down the line they can be mounted to most anything with the right adapter/mount change since they are fully mechanical & were made for 35mm film.
On the overall I'd avoid the Canon FD lenses (great glass but mounting them for infinity focus can be difficult).
My Current Kit:
18mm Sigma XQ f3.2 (also sold as "Spiratone")
24mm Nikkor N.C. f2.8
28mm Nikkor H. f3.5
35mm Nikkor S. f2.8
50mm Nikkor S. f1.4
You can check this link for the vintage nikkors to see some of the differences between them/years made:
[url]
http://www.photosynthesis.co.nz/nikon/serialno.html[/url]
My Personal favorites of these are the 18mm, 28mm, and 50mm (especially the 50mm with a speedbooster, F0.8 is quite cool to shoot at - just a bit slower than Kubricks NASA lenses
).
You can get most of these for next to nothing on Ebay, I paid about $450 for all 5 (the 18mm was the most expensive of them at $150, in scale though a Nikon branded 18mm f3.5 is at $450-$600 buyout right now), with the 28mm (still in its original box, with a Hoya UV filter & caps included) was only $50.
I've also seen good things come out of some of the soviet lenses out there but haven't been able to try any of them out.
That being said, I love my lenses.