If any of you are in to strategy games at all, you have quickly become bored of Civ 5, or you will. The game play is just terrible, IMO. However, I'm still a Civ 4 addict, and I like to install/play mods (the latest Rhye's patch isn't supported on Mac), which isn't supported by the Mac port. You could install Windows with Bootcamp and install the Windows version, but if you don't want to dual-boot, here's a setup that someone figured out and which runs wonderfully for me.
Civ 4 Complete (Windows) on OSX Lion:
http://forums.civfanatics.com/showthread.php?t=464805
Civ 4 Complete (Windows) on OSX Mountain Lion:
http://forums.civfanatics.com/showthread.php?t=472117
Civ 4 Complete (Windows) on OSX Lion:
http://forums.civfanatics.com/showthread.php?t=464805
Civ 4 Complete (Windows) on OSX Mountain Lion:
http://forums.civfanatics.com/showthread.php?t=472117