Amazon has Microsoft Office 2008 for Mac Home & Student Edition quite a bit below the list price (The Apple Store sells it for $98). This is an especially good deal because you get three installation serial numbers in the package, meaning your purchase covers installing on three machines. Microsoft Office is a little on the clumsy side but if you’re getting documents in Word and Excel formats you’ll be glad that you have Office installed.
Another good deal: Apple Airport Express for a little under Apple’s list price of $99. Use this to extend your wireless network, and/or to play your iTunes music from your Mac through your home stereo– wirelessly.
UPDATE: there’s a new version of the Apple Airport Express. Works like the original, but better.
And another: iWork ’09 Family Pack. This is the 5-installation Family Pack, at about the same price as the single-user version at Apple.
Amazon’s prices change so I’m not putting the prices in here. However, their prices are generally the lowest around. Always check them out.