My first post here - you guys make a ton of good points. I'll jump in with 2 well-known contradictions, or seemingly so:
Thou Shalt Not Kill, but:
Numbers 31:17-18 "Now therefore, kill every male among the little ones, and kill every woman who has know man by lying with him. But all the young girls who have not known man by lying with him keep alive for yourselves." So murder everyone including little boys, but keep the virgin girls. Hmmmm....is there an ulterior motive there? Funny how they don't keep alive the virgin boys - just the virgin girls. Maybe the guys liked the excitement of being with virgin women?
Judges 11:30-40: Tells the story of Jephthah wanting to defeat the Ammonites, and being willing to sacrifice "whatever comes out from the doors of my house to meet me when I return in peace from the Ammonites shall be the Lord's, and I will offer it up for a burnt offering." Sadly, that ends up being his only child, a daughter. But hey, a deal's a deal, right?
OK here are 3 bonus ones:
"For I am merciful, saith the Lord, and I will not keep anger forever." (Jeremiah 3:12)
"Ye have kindled a fire in mine anger, which shall burn forever." (Jeremiah 17:4)
"If I testify about myself, my testimony is not valid." (John 5:31)
"Jesus answered: Even if I testify on my own behalf, my testimony is valid." (John 8:14)
"And Jesus coming, spoke to them, saying: All power is given to me in heaven and in earth." (Matthew 28:18)
"the whole world is under control of the evil one." (1 John 5:19)
These are simple ones - but the Numbers one stands out for me. Think of it this way: if you argue that Moses was "commanded by God" to slaughter an entire village (except the virgin chicks), then how exactly is that any different from Muslims flying planes into the World Trade Center and saying God told them to do it? I would suggest it isn't - and that maybe Moses was insane (as evidenced from the 603 completely non-sensical, maniacal laws we see throughout Exodus, Deuteronomy and Leviticus). I welcome any comments - and good to be onboard! I'm a new atheist (as of October 2012, but had been researching for a couple of years, including studying some basic astronomy).