Houston regular visitor looking for some new/different activities to do

Hey guys, I'm a British guy who regularly visits Houston (due to connections through my wife) and I absolutely love Houston and Texas in general, but I'm kinda sick of doing the same things over and over again. You know, like visiting bars, the Woodlands, malls, stadiums, museums, NASA, Kemah, etc… you know, the popular things that every tourist site has listed.

I noticed a couple of interesting things that were just a little different – like the Hill Country Flyer in Austin, and quirky places like Old Town Spring – and I'd be really keen to find out a few more places/activities like that, that we could do when we visit again this weekend.

As you guys are the experts, I'd love to hear your suggestions, no matter how off the beaten track they are. They don't even have to be just in Houston either. I appreciate any comments and suggestions!