First, hook up your iPhone to iTunes. Make sure autosync is off.
Right click on your iPhone in the left pane and choose transfer purchases. This will get all your apps on the computer.
Now right click on the iPhone and choose backup iPhone (this will have all your game saves, app settings, contacts (but you're also going to sync those in the next step), notes, etc, but not pics from your old computer, songs, videos, etc....all the stuff after ringtones in the middle pane under summary).
Go to the middle pane and choose all the programs you need to sync (but not the stuff after the ringtones). Sync.
Then after consolidating the library in your old mac, copy the iTunes folder to your new mac. Also, copy anything else over to the appropriate place (iPhoto stuff or photos to your new mac, etc.). Then sync everything else and you'll be set on the new mac.
