The Sixth Floor Museum was the only museum I really had time for. Because of the crowd and the audio guide, it took about 3-4 hours. Also the museum store was full of great JFK books!
The John F. Kennedy Memorial was also a great spot, it is a meaningful tribute to JFK.
We also stopped by the Dallas Arboretum and Botanical Garden. They had a fun Pumpkin Fall Festival. There was plenty of Texas decor too!
On the last day we went to Reunion Tower to check out the Dallas landscape. It was really fun and the interactive screen was helpful and told us what each building was.