"Will you lower the rent by $X?"
To which I almost always politely reply, "No." ...and explain the following 2 reasons:
Product: we continually provide a better rental product compared to the competition in the area. My rent home is nicer than your rent home.
Price: my rent is already ~$50 below market. My rent is cheaper than your rent, and my house is nicer.
Market: this can change the conversation, and should be mentioned... In the $1000 - $2000 / month rental market we hold firm on this best product, best price model. Above and below that range things can change a bit - in lower rental markets such as $600-$750 / month I'm more inclined to negotiate rent for a strong applicant who screens well. And above $2000 / month you've really got to take a look at your competition / submarket to be sure you're positioned well.
