Indy is a place I want to visit. There's several phenomenal breweries there.
I'm listening... I don't know of any indy breweries? My previous trips to indy have been Meh at best.
Sun King and Black Acre are the two I would tout as the best in the city. There are quite a few others in the area Sun King is located in, as well, but I don't know of their reputation.
3Floyds is considered the best Indiana based brewery. The are located in Munster, basically in Chicago, though. They distribute over the whole state of Indiana. Beer nerds go absolutely crazy for their releases.
I wouldn't plan a trip there as a vacation destination, I think, but there is plenty of great beer there, if you have to go.