Coming from a country where we have such a great jewish population, this is a 'must' question I always asked my friends or associates. There are variety of answers, mostly because of the different kind of branches of judaism, everyone will reply based on that, how 'conservative' they are too. I found those who are in less conservative groups will freely say that they think Jesus was a great Rabbi but of course not the Messiah and they also say they are not the ones to blame for Jesus's death but the Romans.
Other more conservatives would say he was a great man who made an impact on people, but nothing more than that. I think through the years the concept and the opinion about Jesus of Nazareth have changed in the eyes of the Jewish population. It seems to me that nowdays, almost nobody put in doubt the existance of him anymore like in the old times but there is a feeling of understanding and tolerance.
Nothing made me more happy than two see a family of three who were orthodox jewish become 'Christians' jewish.