Mine was an aquamarine blue iMac G3 (the see-through, cathode ray one), which was already quite outdated at that point. My father got me it from work, they were getting rid of old machines.
I used it mainly for music, my brother shared his huge music library over Bonjour inside iTunes, some basic games like chess and sudoku. I remember him teaching me to use Gimp and Seashore and some basic coding in Smultron. It barely ran YouTube, which I remember vividly because I would play videos via Miro, and trying in Safari or Firefox could straight-up freeze the computer. I must have been 7 or 8 at that point.