I would avoid the WI Dells. I love spending a weekend every summer at the Dells, but it is a tourist trap and many of the hotels are borderline inhabitable. The ones that are nice will cost you an arm and a leg.
I love the Concourse. It is on the Capitol Square which is not really walkable to Camp Randall, but would be a short drive away. If you decide to stay at the Concourse, consider staying in the "Governor's Club". It is basically their Conceirge level. For a few bucks more, you get decent snacks in the evening, continental breakfast, cookies in the afternoon, and my favorite, free cocktails from (I believe) 5pm-10pm! The Concourse is also in a great location for restaurants, shopping, etc.
If you are looking for something closer to Camp Randall, there is a Best Western a few blocks down the street. It's the Best Western Inntowner and the Highland Club on University Ave. My parents stayed there once (okay...it was about 10 years ago) when I lived across the street and were fine with it.