I already have that one, if you're referring to the one by Greenheart Games. I've heard Sim City had lots of technical/server issues..
tguy101 do not get SimCity, there's a way better series called tropico, they are making a new one, tropico 5. If your interested you should read my threadhttp://www.ecocitycraft.com/forum/threads/tropico-5-is-coming-out.65788/ I highly recommend it
Roller coaster tycoon is pretty awesome But it gets kinda boring for me. I suppose I haven't taken time to play in-depth. So many of the tools are far too advanced for my style of casual gameplay. It just gets a bit overwhelming after a while and a bit too "pro". For me, it's a casual game. And then there's the awesome part where you drop elephants in the park and snipe them with the helicopter