The al fresco dining scene should be hopping. Avalon has a great patio, as do Asiatique and L & N Wine Bar.
If you're looking for something more upscale, Le Relais, Lillly's, and Jack Fry's are great.
There are plenty of low-key places--The Mayan Cafe is my favorite. Havana Rumba is good. Artemisia and Cafe Classico (recently started serving dinner) are very cool, with great food.
Vietnam Kitchen is on almost everyone's favorites list. We love Maido, Santa Fe Grill, RAW, and Come Back Inn. Just across the river, Rich O's has killer pizza and their own great beer plus hundreds of others.
Stevens and Stevens and The Restaurants Formerly Known As Gumbo-A-Go-Go are good for lunch.
There are lots and lots more. Check out www.louisvillehotbytes.com for reviews, etc. Also look through the chowhound posts for Louisville restaurant reviews--there have been several recently.
Are you looking for anything in particular?
Try looking around the Bardstown Road area (The Highlands).
There are several small places to chow in that area.
Cafe 360 had great Hot Brown. Very trendy place with with a great menu and great prices. I can't wait to go back there.
Cumberland Brews on Bardstown Rd. is one of my favorite for local micro brew.. the Nitro Porter & Pale Ale are my two favoites.They have a small menu as well..fun happening place.
Check out the upstairs... relax and chill!