I guess it depends on what you want to do. We're here for a month, leaving Feb 15. Like Mike said, the River Walk is cool. If you just want to check out the city, stay down town. I've only used the truck about twice a week. We're golfers, so we played a few games. For us it was more to get away from the polar vortex heading our way, in that aspect this was a successful vacation.
Day trip to Corpus Christi was cool.
If caving is your thing, the Natural Caverns were cool, different levels, easy walk to crawling around.
The Pearl District is neat
The 4 missions are cool if history is your interest,
The Alamo of course
Laser show on the front of the San Fernando Cathedral was kind of cool (about 20minutes)
If you're short of time, the hop on, hop off is always an option.
Margaritas are fantastic.
Al