It may sound dumb, but you can visit Indiana just to get away from it all...I live in the country and I personally enjoy taking a drive in the middle of nowhere, checking out the scenery - a complete opposite from a busy city.
I have lots of people visit and sometimes it's hard to find something to do that is special. If it's race time at the track we have that. The food is ok around here, to many people continue to think Applebee's is a good choice to let truly different and good food succeed around here. We lack any real choice for fish....EXCEPT for Frank & Mary's catfish in Pittsboro.
The Art museum does stand out....unless you are from either coasts and then it's a step down from say LA or NY.
No real lakes or mountains or exceptional forests to speak of....sorry poster but Lake Monroe is just a large mud hole..the water is terrible and way to small with to many boaters i truly nice weather, The Syracuse/Wawasee is nice if you can find someone that owns property or a lodge on the lakes. However BC can be nice if you want to hike in the fall for a quick hike and mountain bike ride if you can bring your own. (not sure if there is a rental house for brown country biking).
It's not all bad, but try to find something that stands out above the rest of the country and lets be honest Indiana is just average in many respects, but it is a nice place to live within a reasonable budget.
Usually what stands out when I have friends & family around here is the large summer/fall BBQ's that people typically put on and how friendly those can be...(and large quantities of food). That is something that I find people remember.
The Indianapolis 500, The Brickyard 400, The Nationals. There are great parks. The Indianapolis Children's Museum, which is very interesting even for adults. Purdue University, Indiana University. The Indianapolis Colts, The Indiana Pacers, The Indianapolis Ice (hockey), The Fever (woman's basketball). The Indianapolis Zoo. The Indiana State Museum. Indiana Beach.
There are a lot of things to keep you busy here. It just depends on what you like.