While I never really had the pleasure of being involved with The Sims 1 for whatever reason...
The game play, albeit totally open-ended, which may be a bit strange at first, is so totally immersive in the long run that one can spend literally hours playing this game and it ends up feeling like 10 minutes!
To make it even better for so-called "modders" like me, the game engine is so open-ended that additions to the game are almost limitless as can be seen by the dozens of third-party web sites that focus almost entirely on add-on, "hacks" and objects for the game.
All that can be said here as far as I am concerned is well done Maxis, and with the two expansion packs that have been released since (and with a third apparently on the way) the fun just doesn't end!