The bourbon trail is fun, but nowhere near Louisville. It would take about an hour just to get to the first distillery from L'ville.
4th Street has a pretty decent night life, lots of bars packed in to one little place. Bardstown road is where most of the artsy/hipster type stuff goes on. There are a couple of really great places to eat there though.
Mark's Feed Store is a local BBQ chain there that has some really decent food. There is another place called Homemade Ice Cream and Pie Kitchen that's pretty good for desert.
Waverly Hills Sanatorium is considered to be one of the most haunted places in the U.S. and is just creepy to be there. They may not be giving tours yet, but that never stopped me from taking a look at the outside of the building.
They just opened up the Louisville Mega Cavern. I have no idea what it's all about, but people say it's a lot of fun.
Churchill Downs is there if you want to see where the most famous horse race in the world is ran every year.
Whatever you do, stay out of the west end of downtown. It's not safe there for anyone. If the street your on has a number, the higher the number the more danger you are in.
http://www.louisvilleky.gov/visitors/
