Mount Bohemia
Not only a killer hike with awesome views in the summer, this hill is home to the Mount Bohemia Ski Resort (aka Boho), the best damn ski hill in the midwest. In my opinion at least. All snow is natural as they don't groom and this makes for the deepest of pow days when a good storm rolls through. During the summer there are access trails that you can hike to reach one of the several cliffy areas on the ski hill which overlook Lac La Belle and Lake Superior in the distance. On a sunny day it is a beautiful view.
To get here, take US-41 north until you reach Delaware. Shortly after you're out of the "town", take a right onto Lac La Belle Road and continue for 4 miles. You'll see Mount Bohemia to your right and a parking lot to your left. Park in the parking lot. There's a trail that will get you towards the top of the hill at a moderate incline, though you could always walk straight up the hill if you wanted to too. There are a couple good viewing spots depending on how far up you want to walk. I'd recommend the lower one personally.
http://www.mtbohemia.com/
Thanks to Andrew Dubay for the pictures!