You might have to try a few different models before you find yourself completely happy. I tend to find that I like having springs on my saddle, as it smooths out all the little bumps and road-shocks that would otherwise go straight up your spine.
If you have a background as a road-cyclist, then a B17 is probably best for you, as you will appreciate how the leather moulds itself to fit you, but your pedalling style will find springs too bouncy. If you are anything like me, and started out as an over-weight slob with a fat backside (I'm 6'2" tall and currently 108kg) you'll probably want to opt for a B67, which is wider and sprung. If your backside is a bit skinny, then a Brooks Flyer is the same width as the B17, but has springs.
I use a B67, because that was what I managed to get my hands on cheaply and I have grown to love it.