I have to agree with Mwedzi. Overall, the Walker books are the best. Sure the Vogue books have the pictures in color but really that isn’t that important. The color of most of the swatches in the first volume is a ghastly green.
The cable volume of the Vogue books is fairly nice but I don’t think that it is better than the Walker books. The Vogue books have the lace stitches mixed in with the regular knit and purl which is not handy if you like lace. The number of lace patterns is inadequate. The Vogue books are also a very unwieldy size and shape.
The Walker books have the stitches well organized. There is helpful knitting technique information provided not only for individual stitches but at the beginning of each section also.
If you really want a stitch dictionary with photos in color a much less expensive alternative is the Harmony Guides to Knitting Stitches. If you get volume 2 and 3 you will have plenty of stitch patterns (almost 900) to last you a good long time and they are only about $12 each so you can get both for less than one of the Vogue books.