"2013-07-18 11:42:11 [sEVERE] [ForgeModLoader] There is a binary discrepency between the expected input class net.minecraft.client.Minecraft (ats) and the actual class. Checksum on disk is 5ca8f1e6, in patch aa95f186. Things are probably about to go very wrong. Did you put something into the jar file?" You are OBVIOUSLY not using a clean jar.
If using optifine PLEASE, follow their install instructions, if not, tell the author base modding is bad, he should stop it.