@davidh219: I live in Illinois and some co-workers recommended that place after they went last summer. I was actually thinking about taking a trip by myself somewhere soon, and Wisconsin was pretty high on the list. It's always been just a short drive away, but I've never actually been there. Now you've pretty much sold me on House on the Rock. I think I'm going to start planning this trip now.
You won't regret it. Go eat at Bob's Bitchin' BBQ while you're there. It's right by the House on the Rock hotel. Great food. Amazing guacamole. =)