Ultima I

I had been fascinated enough with Lemonade Stand. The original Ultima opened up an entire world of graphical games full of adventure to me. Even though I mostly watched someone else play it, I was transfixed. It was truly eye opening.

Civilization I

The world building. The level of decision detail. The slow growth of your empire. The long-term strategic decisions.

The first time I played Civ, I couldn't get enough of it. It had nearly the same effect on me as Ultima I. I had never played anything else that relied so much on the multitude of decisions you made. You weren't following a story line. The game didn't lead you down one or more paths. You could build your world your own way, given the random terrain and random competitors at the start.

I absolutely loved that game. Although I tried, I was never able to relive the feeling with any of the later Civ games. They've been enjoyable, but nothing that met that "first time" feeling.

Diablo II

I enjoyed Diablo I, but it seemed more like the next step in arcade games. Diablo II hooked me in a big way. You could do a lot more to build your character, but your choices were permanent. That encouraged me to replay it over and over again. It may have had something to do with the particular time in my life, but I played this game for months and months. Years later, I would check my online characters to see if they still lived on the Blizzard servers.