Not exactly no-go zones, but roads I tend to avoid are the A25 between Gomshall and Dorking and the A24 between Horsham and Capel. Both cases are examples of narrow fast roads with lots of blind corners, blind summits, and drivers not necessarily expecting to encounter cyclists.
Unfortunately when I have to cycle between Holmbury St Mary and North Holmwood it is either the A25 or the nasty descent down the hill from Coldharbour, so it is a choice between risking abuse from drivers on the main road or risking a fall on a poor quality country lane.
I don't find that section of the A25 too bad. Not that I would use it in it's entirety given the plethora of awesome lanes surrounding it, but I frequently ride sections of it to connect up routes.