Hello, I'm a Mac user myself !
If you want a gaming laptop, you'll need to pay the price... Intel Iris cards have compatibility issues with the Sims 3, and a gaming laptop with a NVIDIA card costs about 3000 € / $... If you're open to a desktop Mac, you can get a refurbished one for half the price.
Here is an example of a laptop that would be perfect for the Sims 3 :
http://www.apple.com/shop/product/G0RD2LL/A/Refurbished-154-inch-MacBook-Pro-28GHz-Quad-core-Intel-i7-with-Retina-DisplayFor comparison, this is my own desktop I'm playing the Sims 3 with :
http://www.apple.com/shop/product/FE087LL/A/refurbished-215-inch-imac-29ghz-quad-core-Intel-Core-i5Almost the same specs, but much cheaper than the laptop !
With 3 or 4 EPs, you can play the Sims 3 on Mac in windowed mode (1024 x 768), on medium-low graphical settings, but you'll certainly have "exception raised" errors that will crash your game. For that reason, you need to save regularly, every 15 minutes is good. And your computer won't like custom content (CC) much. What I recommend is to use BootCamp to install a small Windows partition on your Mac (dual boot) so you can play on high settings without issues, with all add-ons and CC. It's really worth it. If you're interested in this option and want more information, I can help you.
Honestly, I think that the best option is either a desktop Mac or a gaming PC. Not really a MacBook pro unless if you have the very high budget mentioned above...
And now that I think about it, laptops tend to overheat with the Sims 3, and MacBooks in particular are known for causing fires... So if you really want a laptop, buy a cooling mat. But really, I'd rather buy a desktop if I were you...
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Spore runs on Mac on highest settings (although like with the Sims 3, you may have "exception raised" errors), but if you don't want to have a black screen (there is sound but no picture) when it starts, you need to edit a file first. Do this once Spore (and also its add-ons if you have them) is installed.
First, you need to access your user's library. This folder is invisible, so you need to do something to view it. Go to Applications --> Utilities and open Terminal. Enter the following commands (with the exact same syntax, don't add or remove spaces) :
defaults write com.apple.finder AppleShowAllFiles -boolean true ; killall Finder
Press enter, and quit Terminal.
Now you should see invisible files on your Mac. They look lighter (in color) than other files. They're necessary for your system, so in general, don't touch them.
Go to user's folder, and right-click on library to open this folder in a new tab ; go to Preferences --> Spore preferences --> right-click on Config to open it with TextEdit. Look for the line with "fbobackbuffer", and change "0" to "1" (don't change anything else as the syntax must stay exactly the same). Save (not "save as", just "save") and quit. Spore should execute normally now. If it doesn't, playing in windowed mode a few times can help although it will look bugged as well as Cider has some graphical problems with Spore, but there's no reason it won't run normally in the end.