I live in Milwaukee. Personally I really like it, I think it's super underrated when it comes to the national level.
The best: In my completely biased opinion, we're the best city in the world for craft brewing. Stuff is pretty inexpensive here as well... we're basically a smaller, cheaper Chicago. We've got some awesome museums, the beautiful Lake Michigan, super passionate sports fans and a lot of cool bars to head out to, especially if you're looking for a great beer selection. We also have some of the cleanest tap water in the world.
The worst: This one doesn't effect me all that much, but we are the most racially segregated city in the United States. Not a great title to claim. Winters are long and cold and since we're next to the lake, the snow we get is often really wet and sloppy.