Click on the attractions link in TripAdvisor to see several comedy clubs, theater, nature experiences, and activities! If you have kids, Disney and Universal are only FUN when the weather is moderate, the crowds are minimal, and then, they are only FUN for about 2 hours... and then everyone is too overwhelmed. Your kids WILL remember the wild animals on adventure walks, the swimming pool, and the fun they had with mom and dad... they will not remember anything but how grumpy everyone gets waiting in line for food and rides!
Even with kids under 18, you can go to any "night club" and listen to music until 11:00 at least. We love BB King's Blues Club in the one of the shopping malls. Even here, they have several good, affordable restaurants that have live music. At BB King's, you can even talk with the members of the band to get them to improvise some really good original stuff. A musician's dream to hear this talent. (We have a very musical family.)
From the "activities" link, I have 30 websites of things I have planned for our December 2013 trip to Kissimmee. I wish I would have had trip advisor for the last 3 trips to Orlando! We even have a couple of days set aside for surfing at Ron Jon's in Cocoa Beach, and then a few more days for the gulf coast, just for warmer a beach experience! Its not that far, and so worth the fun!
Edited: 10:20 am, November 17, 2013