I vividly remember Illinois beating us every year when I was a little kid, which caused me to really dislike them. It made me sick that that game was so close this past year, especially with them having another "down" year. Zook just gives me another reason to not like 'em.
Wisconsin is like the neo-Illinois to me. They've beaten us more often than any other Big Ten team in recent memory. Hard to get them dancing on our O at midfield after they beat us one time in the 'Shoe. Plus, with the exception of Bernini and the classy Wiscy fans that frequent this site, they have arguably the worst game-day fans in college football. Rude, drunk, and confrontational to fans of the opposition. I have TONS of respect for the team, but there is no love lost there.
Overall, hard not to respect anyone in your conference because the moment you don't respect them, they beat you. The only schools I can think of that I have little respect for are for those that bend rules to get a leg up against their competition, which most often pertains to recruiting theories/morals and how a team disciplines their players for breaking the law.