Kristine,
My friend's 10 year old son loves Roller Coaster Tycoon, and her husband loves it too (40ish). I played it for a while and thought it was great. I would recommend it to anyone who likes building things. Roller Coaster Tycoon is explained in the Rouse book as well.

I don't know anyone who doesn't like the SIMS, but I haven't played it. I know three families who have it, and two of the families didn't want their children under 14 or so playing it.

So there you go!