Michter's does random drops every day and offers Fill Your Own about 3-4 times per week. It's always Barrel Strength Bourbon between 108-116 proof. I haven't tried this one yet, but I've had it before and it has a great fruit note added to their regular bourbon profile.
Get to Michter's 30 minutes before they open at 10am to get in line. Earlier if it's a weekend. They will announce whether they are doing Fill Your Own when they open the doors and you can go in and book your time. They had it at 11:30 and 1:30, which is pretty standard from what I've heard.
They will also drop bottles and bundles throughout the day. Usually two drops that could be morning or afternoon. For example, they didn't do a drop the morning I was in line, but they dropped M10B bundled with the American Whiskey around noon, and Barrel Strength Rye around two that day.
I've heard if you go up to the Michter's bar you can talk to the bartenders and they will give you a heads up if there is a drop. The tour is not worth it though, especially if you do fill your own.
The Old Forester tour is one of the best I've done though. Seeing them fire barrels in the cooperage at the end of the tour was very cool. Like Michter's this is right on whiskey row in Louisville.
Old Forester also dropped Presidents Choice while I was there, but I'm an idiot and went to the bar instead of buying it right then. It didn't last long. The bar is awesome though, and for $50 you can get a pour of the Birthday Bourbon, a 117 series, and Presidents choice. All excellent pours.
Beyond that, I highly recommend Doc Crows for a meal. Good southern food. The shrimp and grits were great, but the fried pork chops stole the show. Best chips I've ever had in my life. Make sure you get the "hot" fried instead of the regular.
Churchill Downs is a good tour for a change of pace. We got lucky and got to watch a race while we were down at the track. That was insane.
Louisville Slugger is a must do in my opinion even if you aren't a baseball fan. The renovation to the museum is awesome. They let you hold the bats of famous players - Babe Ruth, Hank Aaron, Roberto Clemente, etc. The tour is under half an hour and they do tours every 20 minutes. You can literally walk in whenever and do it. At the end each person gets a free mini bat to take home. Great souvenir if you have kids and just really cool to see how they make the bars to this day. We got lucky and were able to see a lady making one by hand, but the machine lathes are cool to see too.
It's a great food town with lots to tour and hard to find pours everywhere you go. You can try half pours of all the unicorns you want at good prices.
Also, if you make it out to Bardstown, I highly recommend the barrel thieving tour at Bardstown Bourbon Company. The bourbon slushie that you can take on the tours with you is the best mixed drink I've ever had.
Finally, lunch at the Jim Beam distillery is a great option halfway between Louisville and Bardstown. Amazing food and cocktails. The pepperoni pizza with hot honey was so good. Same with the empanadas and duck poppers. It's a great way to grab lunch and walk the grounds without having to do another tour.