P.
What about Lake Geneva? It's really close and it's a nice place to go for a little trip. I can't help you out with where to stay though. We stayed at the Abby Resort, which was nice, but I'd like to stay someone else the next time around, since we prefer hotels that offer suites, so we have two rooms instead of one.
Another place we use to go to when I was a little girl is Holland Michigan. Saugatuck is close by, which is a cute little town. Holland has a nice lake and beach and has many cottages for rent.