Me.
I was a previous addict to Sims 1, and I'm to the V2.0. Altough you can't make your own aliens babies. You have to wait for one of your characters to fall in love with the current aliens.
My addiction to games come in circles : once is Sims, once is Age of Empire, once Diablo 2 or Legacy of Kain, and every time i come back to Alpha Centuri and Civilization 3. i can ploay on almost everything except FPS and soccer simulations
One good thing of this version is that once you've designed two member of a family you can set them up as lovers. So they go directly in the same bed without fuss. No trouble with having a spere bed for one time.
Foxbat, torturing your creation is one part of the joys of this game.
I'm not mean to my sims, I try to be nice to them, because I feel sad when they make despairing faces at me if they aren't happy.
Cal, make them flirt lots, and it should work.
I used to have a problem with my sims always being very fat, but I found out that a swimming pool is the right solution to that problem, even a very small cheap one.