It's a love and hate relationship or give and take :-)
As designers we need to satisfy our clients demands/requests so at the end of the unhappy client = bad rep or no pay day :-(
I like to meet with my clients hear them out, let them show me sites they like and sites they want their product to resemble or have similar features. From there I put on my headphones and go to work in a few hours or days I come up with a 1st draft solution. (Note: hopefully your client can understand wireframes and does not request high fidelity mockups. ;-) )
We meet I present we discuss and make modification hopeful not to many. Like this I can move on to high fidelity or final designs and then prototyping/coding out the site.
Now if you have client who believes they understand design, interaction and technology along with human behavior patterns better then you and will not except your professional opinion, recommendation or design. Your left with nothing else but having to pull out the big guns. What I mean hear is start referencing books, ux standards and procedures etc. follow up with competitor info on who failed and who succeeded with your recommendations.
If that fails, hang it up!
Very important to know when to retreat and when to stand up for a battle.
hope that helps.