This is my favorite of The Sims. The original got me hooked onto the series, but I played The Sims 2 like a maniac. There was one day I played for sixteen hours straight, without needing to eat or use the bathroom or anything, just because I was so entrenched in the game. I was younger then, and with more free time, but this game is still a classic to me. I haven't latched on to any of its sequels in quite the same way. I think the genetics of this game were the best, and I loved the ways you could play with family structure.