Lol, ya I love The Sims (My name is proof of that). It is really really addicting, they've really made so many improvements with The Sims 3 it makes for a much better experience. I love being able to go around a open neighborhood, and just everything you can do now in general.
So ya, both because it is fun and because it is new, but I tend to really get carried away with The Sims.
If you have a fairly decent laptop you can run it. I was excited about The Sims 3 when it was announced but I thought I wouldn't be able to run it either (I am playing off of my laptop as well). Then I checked the minimum specs at http://www.systemrequirementslab.com and saw my laptop could actually run it. Although I can't have everything at the top (which sucks because The Sims 3 is simply beautiful at full graphics) it looks good and plays well too.
So ya, both because it is fun and because it is new, but I tend to really get carried away with The Sims.