The smallest things make my better half the happiest. Every time he tells me something new he loved as a child, a snack he sometimes craves, I store that bit of information away in my brain to bring out at a later time and surprise him.
Sometimes its the smallest momento I find in a gift shop that bears meaning solely to us, once it was a specially designed lighter, another time perfectly ripe cherry tomatoes (one of his favorite snacks).
That being said, though small things give me a great deal of satisfaction, I cannot claim to be nearly as low-maintenance as him by any means.