I was a very satisfied C64 owner (the happy recipient of my parents' xmas gift). After about 3 years, my dad told me his friend at work (who used to get us games for the C64), switched to an Amiga. I was in a computer store and saw the amazing Amiga demos that were running and well, I just had to get it! The first demo I saw was Dungeon Master. My jaw fell on the floor.
I took the savings I made from my high school job, bought the 500, and was able to trade games again with my dad's work friend. The 500 took me all the way through college making me several friends in the process. No one I met had ever heard of an Amiga in college, but before I knew it, half my floor was in my dorm room playing Omni-Play Basketball and TV Sports Football.
I still can't believe that was half a lifetime ago!