M.R.
if you are looking for something in-town i would suggest Malibu speedzone (go-karts and games for adults and kids) and Zero Gravity which is right next door. Zero Gravity offers bungee jumping, free-fall, and sky coasters. We did both for my husband's 30th and he said he felt like a kid - we had so much fun! Here are the websites:
http://www.speedzone.com/dallas.html
http://www.gojump.com/index.aspx