Crucifixion has come to be identified with the person of Jesus to the point that we sometimes forget that Jesus was just one of many, many people that were executed this way. The gospels themselves provide this evidence for us when we are told that two thieves were also executed with Jesus.
But by making a mode of execution a central part of Christian theology, the horror of the cross is mitigated. We use crosses as jewelry, tattoos and wall hangings. But as I have heard people say from time to time, we would all look twice if we saw someone wearing an electric chair or a guillotine around their neck. The hangman's noose is not something that we normally would expect to see gracing the walls of our living room.
Over at the NT Pod Mark Goodacre has recorded an excellent little piece on the horror of crucifixion. Mark discusses the archaeological literary evidence that we have for crucifixion. And unlike the Lead Codices and the supposed nails from Jesus' cross, Mark provides you with information that is not only relevant to Easter season but can also be of some help in your preaching and teaching.
Listen to it here.