I like the colour saturation of Fuji Velvia as well, and I eagerly awaited the introduction of the med speed Velvia F100. However, it really seems a different film. The main difference seems to be in rendering the colour of clear blue sky and some greens. They seem to come out rather flat and greyish, as if the cyan is not being activated sufficiently, relative to the other layers.
RPV 50 - can't beat it for rich saturated colours. Kodak Ectachrome seems to come close, but much warmer colour rendering. Provia also good, more subtle.
As for B&W - Genes suggestion of Ilford films, I agree with. FP4+ (ISO125) or worth trying Kodak TRX, great for a faster film (320).