Two stick out to me in particular.

The first one was at the Cajun Skillet in Cedar Park (I know I know) We went there soon after they opened and the owner offered us a free sample of their daiquiris. We said sure, fully expecting a tiny little sample sized cup. Nope, it was a full 12-16oz cup. That and the food got me feeling so good that morning, it was awesome.

The second one was Taqueria Jessica up North on McNeil. I asked for a tamarind water and the owner said he was out of cups. I was visibly disappointed and he said to give him a second before coming back with a huge container that they normally use for menudo, full to the brim with my tamarind water. Dude stabbed the lid with a knife, stuck a straw in, and handed it to me free of charge. Those are some of the best tacos I've ever had too, by the way.