Since Louisville is in the thread title, here's one at the south end of Indiana with about half in Kentucky:
If anyone is interested in this I'll have to give more detail maps of turns. The Kentucky side is not well marked. Most of the Indiana side is the Ohio River Road, but cuts off to go through some fairly deep forest past Buzzards Roost.
This route begins at 135 and the Ohio River Road in Corydon. It crosses the river into Kentucky then follows the river to Hawesville, crosses back over to Cannelton, then heads east on the Ohio River Road.
Lunch at the Overlook, a down home style restaurant overlooking the horse shoe bend of the Ohio River. Ice Cream at
Emery's Ice Cream Parlor (if they're open, and yes, it looks like the web site).
There's a lot of great scenery on this one. This one isn't quite as popular with my touring bike buddies as the Brown County route, but that's primarily because it's long enough you really need to spend two nights in Corydon to do do it right. Of course that usually means Friday night dinner of frog legs or plate size tenderloin at The Dock right on the river in old Leavenworth - you can watch the barges go by on the river within rock throwing distance.
This one has several good photo op spots.