“I contend we are both atheists, I just believe in one less god than you do. When you understand why you dismiss all the other possible gods, you will understand why I dismiss yours.” —Stephen F Roberts
Funny thing is I've heard this same argument multiple times from atheists who comment on John Lofus' blog Debunking Christianity. I've posted links to the answer for this objection in several posts on this blog from several people. I like this particular treatment also.
Why the “I Just Believe in One Less God than You” Argument Does not Work | Parchment and Pen