I think Minnesota is the most prestigious of the 3. It's a perennial Top 20. However, I'm not sure that it's placement is really any more national, perhaps if you're yop 10% or something. But I've been deferredthere so pick Wisconsin or BC -- sounds like you have a personal prference for one of those schools anyway.
According to most published reports, BC places in BIGLAW better. http://www.law.com/jsp/nlj/PubArticleNLJ.jsp?id=1207904889529However, I would suggest the following:If you want to practice at a big firm on a coast, attend BC.If you want to work in the MidWest, attend UMinn. (other than Wisc).If you want to work in Wisconsin, attend Madison.