I only had a 16KB version, not the 48KB one.
I had a couple of games which were basically copies of the old arcade classics Space Invaders and Asteroids.
I remember the magazines full of code that you were supposed to type in!
I wrote my own pointless computer programs for the Spectrum, just to see if I could get them to work. One drew a picture of E.T. (The Extra Terrestrial) and then played the movie theme! Another was a database of all the players in my favorite football club (name, date of birth, etc.)
I gave one friend a copy of my programs on an old cassette and then a few weeks later I learned that other kids in my class had seen them as well. It turns out there was a bunch of kids who were obsessively collecting and swapping programs, which is kind of funny to think about. Like an early 1980s version of peer2peer file sharing!