OK, so let's get the pun out of the way first...
I decided to treat my waterproofs the other day... Took them to the Zoo... They loved it!!
Anyway. I swear by Nikwax, and use the actual wax for boots etc (best applied by fingers to add a little warmth and aid the penetration process), and the Nikwax TX Direct Spray-on for my gore-tex jacket and trousers.
Proof of the pudding was a 15 minute deluge, with hailstones and the - french - road turning into a river.
Not a drop did penetrate.
Despite this, I always wonder, for leather (boots) and gore-tex (trousers and jacket) does anyone else have any "miracle products" which they recommend?