The other day I stumbled across the site JesusNeverExisted.com and was blown away. The site is fantastic! It puts the words to my own rejection of Christianity and backs words with facts I only vaguely knew/suspected. The site and its author brilliantly attack the foundations of Christianity and its many claims through logical and historical arguments, most of the time using the church's own writings/teachings to make the points. The site also offers fascinating contextual information about how the bibles were shaped, and upon what other documents and religions they were based.
I wanted to hate this site, when I first clicked the link to get there I expected the worst, the title being so "in your face". Arguments against Christianity (from atheists, especially) usually feel exhaustingly and frustratingly religious (in their own way), without any real facts, but this site instantly had me hooked because it lays out the arguments and the facts so well (and the facts are often conflicting quotations from the bible).
This site is unlikely to convince any true believer that they have been mistaken, but it surely would give a nudge to someone already on the fence.